Membrane Proteins of Known Structure

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mpstruc is a curated database of membrane proteins of known 3D structure. To be included in the database, a structure must be available in the RSCB Protein Data Bank (PDB) and have been published in a peer reviewed journal. The database is manually curated based upon ongoing literature surveys. Because of the labor involved, new structures are not posted until they are released by the PDB and the complete reference, including pagination for print journals, is available in PubMed. Our goal is to make mpstruc as accurate and complete as possible. If you find errors or omissions, please send a message to Gracie Han, or mpstruc emphasizes structures determined by diffraction and cryo-EM methods. NMR structures are also included whenever identified. A comprehensive list of NMR-determined structures has been established by Dror Warschawski and is available from the Atoine Loquet lab.

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Members of the Bridge Institute at USC join the mpstruc team: We're pleased to announce that the Ray Stevens and Vadim Cherezov labs will join us in maintaining and improving the mpstruc database. Dr. Gye Won "Gracie" Han will be the voice of the group.
Membrane-embedded structures now available!: Mark Sansom's lab at Oxford has created the MemProtMD database of all known transmembrane proteins embedded in lipid membranes, described in Stansfeld et al. (2015) Structure 23:1350-1361. Links to the structures are now included in mpstruc. Click on the icon, and you will be taken to the appropriate entry in MemProtMD.
MPtopo XML data representations now available: XML representations are now available for the MPtopo membrane protein topology database.

Latest new protein entered: 20 Nov 2024 at 10:07 PST.
Last database update: 20 Nov 2024 at 10:19 PST

Recently Added Structures:

HCA3 hydroxycarboxylic acid receptor 3 - G_i complex with bound compuond 5c: Homo sapiens, 2.73 Å
Photosystem I + ferredoxin supercomplex: Pisum sativum, 2.50 Å
succinate receptor SUCNR1 (GPR91). Humanized (K18E, K269N mutant) in complex with a Nb and antagonist: Rattus norvegicus, 2.27 Å
Atm1-type ABC exporter with MgADP bound: Novosphingobium aromaticivorans, 3.70 Å
Glucagon receptor-G_s complex bound to a designed glucagon derivative: Homo sapiens, 3.10 Å
YbtPQ ABC importer: Escherichia coli, 3.67 Å

Unique proteins in database = 1737

Coördinate files in database = 7967

Published reports of membrane protein structures in database = 3464

A full list of pdb codes currently in the database is available here.

Unique proteins include proteins of same type from different species. For example, photosynthetic reaction centers from R. viridis and R. sphaeroides are considered unique. Structures of mutagenized versions of proteins already in the database are excluded as unique. Proteins that differ only by substrate bound or by physiological state are also excluded. Structures 'obsoleted' by the PDB are not included.

Total number of PDB coördinate files, including those for unique proteins. This number reflects the fact that published reports of structures often include several coördinate files describing, for example, the protein in different crystal forms, or with different bound substrates.

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Links to the Protein Data Bank Site

Links to the Structural Biology Knowledgebase Site

Membrane Proteins of Known 3D Structure
(Table description)
Protein	PDB Code	Links	Reference (links are to PubMed)
MONOTOPIC MEMBRANE PROTEINS Reviewed by Allen et al. (2018) Database of Peripheral Membrane Proteins
Cyclooxygenases
*Ram Prostaglandin H2 synthase-1 (cyclooxygenase-1 or COX-1): Ovis aries* E Eukaryota, 3.5 Å**	1PRH	Data File Jmol Viewer prostaglandin synthase-1 (COX-1)	Picot et al. (1994). Picot D, Loll PJ, & Garavito RM (1994). The x-ray crystal structure of the membrane protein prostaglandin H₂synthase-1. Nature 367 :243-249. PubMed Id: 8121489.
*Ram Prostaglandin H2 synthase-1 (COX-1): Ovis aries* E Eukaryota, 3.4 Å** In complex with bromoaspirin.	1PTH	Data File Jmol Viewer	Loll et al. (1995). Loll PJ, Picot D, & Garavito RM (1995). The structural basis of aspirin activity inferred from the crystal structure of inactivated prostaglandin H2 synthase. Nat Struct Biol 2 :637-643. PubMed Id: 7552725.
*Ram Prostaglandin H2 synthase-1 (COX-1): Ovis aries* E Eukaryota, 3.1 Å** In complex with flurbiprofen.	1CQE	Data File Jmol Viewer	Garavito et al. (1995). Garavito RM, Picot D, & Loll PJ (1995). The 3.1 A X-ray crystal structure of the integral membrane enzyme prostaglandin H2 synthase-1. Adv Prostaglandin Thromboxane Leukot Res 23 :99-103. PubMed Id: 7732912.
*Ram Prostaglandin H2 synthase-1 (COX-1): Ovis aries* E Eukaryota, 2.61 Å** 1EQG is complex with ibuprofen. Complex with flurbiprofen, 2.70 Å: 1EQH Complex with flurbiprofen methyl ester, 2.75 Å: 1HT5 Complex with alclofenac, 2.69 Å: 1HT8	1EQG	Data File Jmol Viewer	Selinsky et al. (2001). Selinsky BS, Gupta K, Sharkey CT, Loll PJ (2001). Structural analysis of NSAID binding by prostaglandin H2 synthase: time-dependent and time-independent inhibitors elicit identical enzyme conformations. Biochemistry 40 :5172-5180. PubMed Id: 11318639.
*Ram Prostaglandin H2 synthase-1 (COX-1): Ovis aries* E Eukaryota, 3.2 Å** In complex with O-actylsalicylhydroxamic acid.	1EBV	Data File Jmol Viewer	Loll et al. (2001). Loll PJ, Sharkey CT, O'Connor SJ, Dooley CM, O'Brien E, Devocelle M, Nolan KB, Selinsky BS, & Fitzgerald DJ (2001). O-acetylsalicylhydroxamic acid, a novel acetylating inhibitor of prostaglandin H2 synthase: structural and functional characterization of enzyme-inhibitor interactions. Mol Pharmacol 60 :1407-1413. PubMed Id: 11723249.
*Ram Prostaglandin H2 synthase-1 (COX-1): Ovis aries* E Eukaryota, 2.00 Å** In complex with alpha-methyl-4-biphenyl acetic acid.	1Q4G	Data File Jmol Viewer	Gupta et al. (2004). Gupta K, Selinsky BS, Kaub CJ, Katz AK, & Loll PJ (2004). The 2.0 Å resolution crystal structure of prostaglandin H2 synthase-1: structural insights into an unusual peroxidase. J Mol Biol 335 :503-518. PubMed Id: 14672659.
*Ram Prostaglandin H2 synthase-1 (COX-1): Ovis aries* E Eukaryota, 2.00 Å** In complex with flurbiprofen + Mn(III) PPIX cofactor.	2AYL	Data File Jmol Viewer	Gupta et al. (2006). Gupta K, Selinsky BS, & Loll PJ (2006). 2.0 angstroms structure of prostaglandin H2 synthase-1 reconstituted with a manganese porphyrin cofactor. Acta Crystallogr D Biol Crystallogr 62 :151-156. PubMed Id: 16421446.
*Ram Prostaglandin H2 synthase-1 (COX-1): Ovis aries* E Eukaryota (expressed in Spodoptera frugiperda), 3.05 Å** 3N8V is the unoccupied structure. R120Q/Native Heterodimer mutant in complex with Flurbiprofen, 2.75 Å: 3N8W COX-1 in complex with Nimesulide, 2.75 Å: 3N8X Aspirin Acetylated COX-1 in Complex with Diclofenac, 2.60 Å: 3N8Y COX-1 in Complex with Flurbiprofen, 2.90 Å: 3N8Z	3N8V	Data File Jmol Viewer	Sidhu et al. (2010). Sidhu RS, Lee JY, Yuan C, & Smith WL (2010). Comparison of Cyclooxygenase-1 Crystal Structures: Cross-Talk between Monomers Comprising Cyclooxygenase-1 Homodimers. Biochemistry 49 :7069-7079. PubMed Id: 20669977.
*Ram Prostaglandin H2 synthase-1 (COX-1) in complex with the subtype-selective derivative 2a: Ovis aries* E Eukaryota (expressed in Spodoptera frugiperda), 3.35 Å**	7JXT	Data File Jmol Viewer	Friedrich et al. (2021). Friedrich L, Cingolani G, Ko YH, Iaselli M, Miciaccia M, Perrone MG, Neukirch K, Bobinger V, Merk D, Hofstetter RK, Werz O, Koeberle A, Scilimati A, & Schneider G (2021). Learning from Nature: From a Marine Natural Product to Synthetic Cyclooxygenase-1 Inhibitors by Automated De Novo Design. Adv Sci (Weinh) 8 16:2100832. PubMed Id: 34176236. doi:10.1002/advs.202100832.
*Prostaglandin H2 synthase-1 (cyclooxygenase-1 or COX-1): Homo sapiens* E Eukaryota (expressed in Spodoptera frugiperda), 3.36 Å**	6Y3C	Data File Jmol Viewer	Miciaccia et al. (2021). Miciaccia M, Belviso BD, Iaselli M, Cingolani G, Ferorelli S, Cappellari M, Loguercio Polosa P, Perrone MG, Caliandro R, & Scilimati A (2021). Three-dimensional structure of human cyclooxygenase (hCOX)-1. Sci Rep 11 1:4312. PubMed Id: 33619313. doi:10.1038/s41598-021-83438-z.
*Cyclooxygenase-2: Mus musculus* E Eukaryota, 3.0 Å**	1CX2	Data File Jmol Viewer prostaglandin synthase-2 (COX-2)	Kurumbail et al. (1996). Kurumbail RG, Stevens AM, Gierse JK, McDonald JJ, Stegeman RA, Pak JY, Gildehaus D, Miyashiro JM, Penning TD, Seibert, K et al (1996). Structural basis for selective inhibition of cyclooxygenase-2 by anti-inflammatory agents. Nature 384 :644-648. PubMed Id: 8967954.
*Cyclooxygenase-2 with bound indomethacin-ethylenediamine-dansyl conjugate: Mus musculus* E Eukaryota (expressed in S. frugiperda), 2.22 Å** with bound indomethacin-butyldiamine-dansyl conjugate, 2.22 Å: 6BL3	6BL4	Data File Jmol Viewer	Xu et al. (2019). Xu S, Uddin MJ, Banerjee S, Duggan K, Musee J, Kiefer JR, Ghebreselasie K, Rouzer CA, & Marnett LJ (2019). Fluorescent indomethacin-dansyl conjugates utilize the membrane-binding domain of cyclooxygenase-2 to block the opening to the active site. J Biol Chem 294 22:8690-8698. PubMed Id: 31000626. doi:10.1074/jbc.RA119.007405.
*Fatty acid α-dioxygenase (α-DOX): Arabidopsis thaliana* E Eukaryota (expressed in E. coli), 1.70 Å** First structure of a member of the α-DOX subfamily of cyclooxygenase-peroxidase family of heme-containing proteins. With bound imidazole, 1.51 Å: 4HHR	4HHS	Data File Jmol Viewer	Goulah et al. (2013). Goulah CC, Zhu G, Koszelak-Rosenblum M, & Malkowski MG (2013). The Crystal Structure of α-Dioxygenase Provides Insight into Diversity in the Cyclooxygenase-Peroxidase Superfamily. Biochemistry 52 :1364-1372. PubMed Id: 23373518. doi:10.1021/bi400013k.
Lipoxygenases Related to Cyclooxygenases Rather than being tethered by α-helices at the interface, they are tethered by N-terminal β-sheet C2-like domains
*Arachidonic acid 15-lipoxygenase from soybeans: Glycine max* E Eukaryota, 2.60 Å**	2SBL	Data File Jmol Viewer	Boyington et al. (1993). Boyington JC, Gaffney BJ, & Amzel LM (1993). The three-dimensional structure of an arachidonic acid 15-lipoxygenase. Science 260 5113:1482-1486. PubMed Id: 8502991. doi:10.1126/science.8502991.
*Lipoxygenase-L1 from soybeans: Glycine max* E Eukaryota, 1.40 Å**	1YGE	Data File Jmol Viewer	Minor et al. (1996). Minor W, Steczko J, Stec B, Otwinowski Z, Bolin JT, Walter R, & Axelrod B (1996). Crystal structure of soybean lipoxygenase L-1 at 1.4 A resolution. Biochemistry 35 33:10687-10701. PubMed Id: 8718858. doi:10.1021/bi960576u.
*Lipoxygenase-L3 from soybeans: Glycine max* E Eukaryota, 2.60 Å**	1LNH	Data File Jmol Viewer	Skrzypczak-Jankun et al. (1997). Skrzypczak-Jankun E, Amzel LM, Kroa BA, & Funk MO Jr (1997). Structure of soybean lipoxygenase L3 and a comparison with its L1 isoenzyme. Proteins 29 1:15-31. PubMed Id: 9294864. doi:10.1002/(SICI)1097-0134(199709)29:1.
*8R-Lipoxygenase from coral: Plexaura homomalla* E Eukaryota (expressed in E. coli), 3.20 Å** 2FNQ supersedes 1ZQ4	2FNQ	Data File Jmol Viewer	Oldham et al. (2005). Oldham ML, Brash AR, & Newcomer ME (2005). Insights from the X-ray crystal structure of coral 8R-lipoxygenase: calcium activation via a C2-like domain and a structural basis of product chirality. J Biol Chem 280 47:39545-39552. PubMed Id: 16162493. doi:10.1074/jbc.M506675200.
*8R-Lipoxygenase from coral. Δ413-417 I805A mutant: Plexaura homomalla* E Eukaryota (expressed in E. coli), 1.85 Å**	3FG4	Data File Jmol Viewer	Neau et al. (2009). Neau DB, Gilbert NC, Bartlett SG, Boeglin W, Brash AR, & Newcomer ME (2009). The 1.85 A structure of an 8R-lipoxygenase suggests a general model for lipoxygenase product specificity. Biochemistry 48 33:7906-7915. PubMed Id: 19594169. doi:10.1021/bi900084m.
*15-Lipoxygenase from rabbit reticulocytes: Oryctolagus cuniculus* E Eukaryota, 2.40 Å**	1LOX	Data File Jmol Viewer	Gillmor et al. (1997). Gillmor SA, Villaseñor A, Fletterick R, Sigal E, & Browner MF (1997). The structure of mammalian 15-lipoxygenase reveals similarity to the lipases and the determinants of substrate specificity. Nat Struct Mol Biol 4 12:1003-1009. PubMed Id: 9406550. doi:10.1038/nsb1297-1003 .
*5-Lipoxygenase: Homo sapiens* E Eukaryota (expressed in E. coli), 2.39 Å**	3O8Y	Data File Jmol Viewer	Gilbert et al. (2011). Gilbert NC, Bartlett SG, Waight MT, Neau DB, Boeglin WE, Brash AR, & Newcomer ME (2011). The structure of human 5-lipoxygenase. Science 331 :217-219. PubMed Id: 21233389. doi:10.1126/science.1197203.
*15-Lipoxygenase-2 (15-LOX-2) with substrate mimic: Homo sapiens* E Eukaryota (expressed in E. coli), 2.63 Å**	4NRE	Data File Jmol Viewer	Kobe et al. (2014). Kobe MJ, Neau DB, Mitchell CE, Bartlett SG, & Newcomer ME (2014). The structure of human 15-lipoxygenase-2 with a substrate mimic. J Biol Chem 289 :8562-8569. PubMed Id: 24497644. doi:10.1074/jbc.M113.543777.
Squalene-Hopene Cyclases
*Squalene-hopene cyclase: Alicyclobacillus acidocaldarius* B Bacteria, 2.0 Å** 2SQC is space group P4₃2₁2. 3SQC, 2.8 Å is P3₂21.	2SQC	Data File Jmol Viewer squalene-hopene cyclase	Wendt et al. (1999). Wendt KU, Lenhart A, & Schulz GE (1999). The structure of the membrane protein squalene-hopene cyclase at 2.0 Å resolution. J. Mol. Biol. 286 :175-187. PubMed Id: 9931258.
Oxidases
*Monoamine Oxidase B: Homo sapiens (Human) mitochondrial outer membrane* E Eukaryota (expressed in Pichia pastoris), 3.0 Å** NOTE: MAOB has a single transmembrane helix that anchors it to the outer membrane (residues 489-515). Nevertheless, we consider it monotopic because the bulk of the 520-residue protein, including the active site, is not located within the membrane core.	1GOS	Data File Jmol Viewer Monoamine oxidase B	Binda et al. (2002). Binda C, Newton-Vinson P, Hubálek F, Edmondson DE, & Mattevi A (2002). Structure of human monoamine oxidase B, a drug target for the treatment of neurological disorders. Nature Struct Biol 9 :22-26. PubMed Id: 11753429.
*Monoamine Oxidase B with bound Isatin: Homo sapiens (Human) mitochondrial outer membrane* E Eukaryota (expressed in Pichia pastoris), 1.70 Å** with bound Tranylcypromine, 2.20 Å: 1OJB with bound N-(2-aminoethyl)-p-chlorobenamide, 2.40 Å: 1OJC with bound Lauryldimethyl-amine N-Oxide, 3.10 Å: 1OJD with bound 1.4-Diphenyl-2-butene, 2.30 Å: 1OJ9	1OJA	Data File Jmol Viewer	Binda et al. (2003). Binda C, Li M, Hubálek F, Restelli N, Edmondson DE, & Mattevi A (2003). Insights into the mode of inhibition of human mitochondrial monoamine oxidase B from high-resolution crystal structures. Proc Natl Acad Sci USA 100 :9750-9755. PubMed Id: 12913124.
*Monoamine Oxidase A: Rattus norvegicus (Rat) mitochondrial outer membrane* E Eukaryota (expressed in S. cerevisiae), 3.20 Å**	1O5W	Data File Jmol Viewer	Ma et al. (2004). Ma J, Yoshimura M, Yamashita E, Nakagawa A, Ito A, & Tsukihara T (2004). Structure of rat monoamine oxidase A and its specific recognitions for substrates and inhibitors. J Mol Biol 338 :103-114. PubMed Id: 15050826.
*Monoamine Oxidase A with bound Clorglycine: Homo sapiens (Human) mitochondrial outer membrane* E Eukaryota (expressed in Pichia pastoris), 3.00 Å** crystal form B, 3.15 Å: 2BXS Monoamine Oxidase B with bound Deprenyl, 2.20 Å: 2BYB	2BXR	Data File Jmol Viewer	De Colibus et al. (2005). De Colibus L, Li M, Binda C, Lustig A, Edmondson DE, & Mattevi A (2005). Three-dimensional structure of human monoamine oxidase A (MAO A): relation to the structures of rat MAO A and human MAO B. Proc Natl Acad Sci USA 102 :12684-12689. PubMed Id: 16129825.
*Monoamine Oxidase A with bound Harmine: Homo sapiens (Human) mitochondrial outer membrane* E Eukaryota (expressed in S. cerevisiae), 2.20 Å** G110A mutant with bound Harmine, 2.17 Å: 2Z5Y	2Z5X	Data File Jmol Viewer	Son et al. (2008). Son SY, Ma J, Kondou Y, Yoshimura M, Yamashita E, & Tsukihara T (2008). Structure of human monoamine oxidase A at 2.2-Å resolution: The control of opening the entry for substrates/inhibitors. Proc Natl Acad Sci USA 105 :5739-5744. PubMed Id: 18391214.
*Alternative oxidase (AOX), cyanide-insensitive: Trypanosoma brucei brucei* E Eukaryota (expressed in E. coli), 2.85 Å** with ascofuranone derivative, 2.59 Å: 3VVA with colletochlorin B, 2.30 Å: 3W54	3VV9	Data File Jmol Viewer	Shiba et al. (2013). Shiba T, Kido Y, Sakamoto K, Inaoka DK, Tsuge C, Tatsumi R, Takahashi G, Balogun EO, Nara T, Aoki T, Honma T, Tanaka A, Inoue M, Matsuoka S, Saimoto H, Moore AL, Harada S, & Kita K (2013). Structure of the trypanosome cyanide-insensitive alternative oxidase. Proc Natl Acad Sci USA 110 :4580-4585. PubMed Id: 23487766. doi:10.1073/pnas.1218386110.
Hydrolases
*Fatty acid amide hydrolase: Rattus norvegicus* E Eukaryota, 2.8 Å** NOTE: Like MAO, FAAH has a single TM segment. But the active site is external to the membrane, and many other residues on the protein surface contribute to membrane binding. Absence of the TM segment affects neither membrane association or function.	1MT5	Data File Jmol Viewer fatty acid amide hydrolase	Bracey et al. (2002). Bracey MH, Hanson MA, Masuda KR, Stevens RC, & Cravatt BF (2002). Structural adaptations in a membrane enzyme that terminates endo cannabinoid signaling. Science 298 :1793-1796. PubMed Id: 12459591.
*LpxH pyrophosphohydrase with bound lipid X & Mn²⁺: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 1.65 Å** complex with lipid X, P21 form, 1.72 Å: 5B4A complex with lipid X, C2 form, 1.6 Å: 5B4B H10N mutant in complex with Mn²⁺, 1.96 Å: 5B4C H10N mutant, 1.75 Å: 5B4D	5B49	Data File Jmol Viewer	Okada et al. (2016). Okada C, Wakabayashi H, Kobayashi M, Shinoda A, Tanaka I, & Yao M (2016). Crystal structures of the UDP-diacylglucosamine pyrophosphohydrase LpxH from Pseudomonas aeruginosa. Sci Rep 6 :32822. PubMed Id: 27609419. doi:10.1038/srep32822.
*LpxI phosphodiester hydrolase for lipid A biosynthesis: Caulobacter crescentus* B Bacteria (expressed in E. coli), 2.90 Å** D225A mutant, 2.52 Å: 4GGI	4GGM	Data File Jmol Viewer	Metzger et al. (2012). Metzger LE 4th, Lee JK, Finer-Moore JS, Raetz CR, & Stroud RM (2012). LpxI structures reveal how a lipid A precursor is synthesized. Nature Struc Mol Biol 19 :1132-1138. PubMed Id: 23042606. doi:10.1038/nsmb.2393.
*LpxK, the 4'-kinase of lipid A biosynthesis: Aquifex aeolicus* B Bacteria (expressed in E. coli), 2.30 Å** Apo LpxK, 1.90 Å: 4EHX ADP/Mg²⁺ LpxK, 2.20 Å: 4EHY	4EHW	Data File Jmol Viewer	Emptage et al. (2012). Emptage RP, Daughtry KD, Pemble CW 4th, & Raetz CR (2012). Crystal structure of LpxK, the 4'-kinase of lipid A biosynthesis and atypical P-loop kinase functioning at the membrane interface. Proc Natl Acad Sci USA 109 :12956-12961. PubMed Id: 22826246. doi:10.1073/pnas.1206072109.
*N-acylphosphatidylethanolamine-hydrolyzing phospholipase D: Homo sapiens* E Eukaryota (expressed in E. coli), 2.65 Å**	4QN9	Data File Jmol Viewer	Magotti et al. (2015). Magotti P, Bauer I, Igarashi M, Babagoli M, Marotta R, Piomelli D, & Garau G (2015). Structure of human N-acylphosphatidylethanolamine-hydrolyzing phospholipase D: regulation of Fatty Acid ethanolamide biosynthesis by bile acids. Structure 23 3:598-604. PubMed Id: 25684574. doi:10.1016/j.str.2014.12.018.
*PulA pullulanase: Klebsiella oxytoca* B Bacteria (expressed in E. coli), 2.88 Å**	2YOC	Data File Jmol Viewer	East et al. (2016). East A, Mechaly AE, Huysmans GH, Bernarde C, Tello-Manigne D, Nadeau N, Pugsley AP, Buschiazzo A, Alzari PM, Bond PJ, & Francetic O (2016). Structural Basis of Pullulanase Membrane Binding and Secretion Revealed by X-Ray Crystallography, Molecular Dynamics and Biochemical Analysis. Structure 24 :92-104. PubMed Id: 26688215. doi:10.1016/j.str.2015.10.023.
*C2 domain of cytosolic phospholipase A₂α bound to phosphatidylcholine: Gallus gallus* E Eukaryota (expressed in E. coli), 2.21 Å**	6IEJ	Data File Jmol Viewer	Hirano et al. (2019). Hirano Y, Gao YG, Stephenson DJ, Vu NT, Malinina L, Simanshu DK, Chalfant CE, Patel DJ, & Brown RE (2019). Structural basis of phosphatidylcholine recognition by the C2-domain of cytosolic phospholipase A₂α. Elife 8 :e44760. PubMed Id: 31050338. doi:10.7554/eLife.44760.
*PlaF phospholipase A bacterial virulence factor: Pseudomonas aeruginosa* B Bacteria, 2.00 Å**	6I8W	Data File Jmol Viewer	Bleffert et al. (2022). Bleffert F, Granzin J, Caliskan M, Schott-Verdugo SN, Siebers M, Thiele B, Rahme L, Felgner S, Dörmann P, Gohlke H, Batra-Safferling R, Jaeger KE, & Kovacic F (2022). Structural, mechanistic, and physiological insights into phospholipase A-mediated membrane phospholipid degradation in Pseudomonas aeruginosa. Elife 11 :e72824. PubMed Id: 35536643. doi:10.7554/eLife.72824.
*Phospholipase Cβ3, in complex with Gγβ on lipid nanodiscs: Homo sapiens* E Eukaryota (expressed in Trichoplusia ni), 3.30 Å** cryo-EM structure on liposomes, 3.50 Å: 8EMW in solution, 3.60 Å: 8EMV	8EMX	Data File Jmol Viewer	Falzone & MacKinnon (2023). Falzone ME, & MacKinnon R (2023). Gβγ activates PIP2 hydrolysis by recruiting and orienting PLCβ on the membrane surface. Proc Natl Acad Sci U S A 120 20:e2301121120. PubMed Id: 37172014. doi:10.1073/pnas.2301121120.
Hydroxylases
*Kdo hydroxylase KdoO, apo protein: Methylacidiphilum infernorum* B Bacteria (expressed in E. coli), 1.94 Å** in complex with cobalt(II), 1.45 Å: 5YKA in complex with alphaketoglutarate and Fe(III), 1.6 Å: 5YVZ in complex with succinate and Fe(III), 1.49 Å: 5YW0	6A2E	Data File Jmol Viewer	Joo et al. (2018). Joo SH, Pemble CW 4th, Yang EG, Raetz CRH, & Chung HS (2018). Biochemical and Structural Insights into an Fe(II)/α-Ketoglutarate/O₂-Dependent Dioxygenase, Kdo 3-Hydroxylase (KdoO). J Mol Biol 430 21:4036-4048. PubMed Id: 30092253. doi:10.1016/j.jmb.2018.07.029.
Acyltransferases
*LpxM lipid A acyltransferase: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 1.99 Å** The protein is anchored at the membrane interface by a single TM helix. E127A catalytic residue mutant, 1.9 Å: 5KNK	5KN7	Data File Jmol Viewer	Dovala et al. (2016). Dovala D, Rath CM, Hu Q, Sawyer WS, Shia S, Elling RA, Knapp MS, & Metzger LE 4th (2016). Structure-guided enzymology of the lipid A acyltransferase LpxM reveals a dual activity mechanism. Proc Natl Acad Sci USA 113 :E6064-E6071. PubMed Id: 27681620. doi:10.1073/pnas.1610746113.
*PatA membrane-associated acyltransferase, unliganded: Mycolicibacterium smegmatis* B Bacteria, 3.67 Å**	7OJT	Data File Jmol Viewer	Anso et al. (2021). Anso I, Basso LGM, Wang L, Marina A, Páez-Pérez ED, Jäger C, Gavotto F, Tersa M, Perrone S, Contreras FX, Prandi J, Gilleron M, Linster CL, Corzana F, Lowary TL, Trastoy B, & Guerin ME (2021). Molecular ruler mechanism and interfacial catalysis of the integral membrane acyltransferase PatA. Sci Adv 7 42:eabj4565. PubMed Id: 34652941. doi:10.1126/sciadv.abj4565.
Thioesterases
*acyl protein thioesterase 1 (APT 1) bound to palmitic acid: Homo sapiens* E Eukaryota (expressed in E. coli), 2.75 Å** C2S mutant bound to palmitic acid, 2.60 Å: 6QGQ S119A mutant bound to palmitic acid, 2.60 Å: 6QGO bound to 2-Bromopalmitate, 2.10 Å: 6QGN	6QGS	Data File Jmol Viewer	Abrami et al. (2021). Abrami L, Audagnotto M, Ho S, Marcaida MJ, Mesquita FS, Anwar MU, Sandoz PA, Fonti G, Pojer F, Dal Peraro M, & van der Goot FG (2021). Palmitoylated acyl protein thioesterase APT2 deforms membranes to extract substrate acyl chains. Nat Chem Biol 17 4:438-447. PubMed Id: 33707782. doi:10.1038/s41589-021-00753-2.
Nucleotidyltransferases
*Tam41 mitochondrial CDP-DAG synthase Δ74: Schizosaccharomyces pombe* E Eukaryota (expressed in E. coli), 2.26 Å** F240A mutant, 2.88 Å: 6IG2	6IG4	Data File Jmol Viewer	Jiao et al. (2019). Jiao H, Yin Y, & Liu Z (2019). Structures of the Mitochondrial CDP-DAG Synthase Tam41 Suggest a Potential Lipid Substrate Pathway from Membrane to the Active Site. Structure 27 8:1258-1269.e4. PubMed Id: 31178220. doi:10.1016/j.str.2019.04.017.
Oxidoreductases (Monotopic)
*Sulfide:quinone oxidoreductase in complex with decylubiquinone: Aquifex aeolicus* B Bacteria, 2.0 Å** "as-purified" protein, 2.30 Å: 3HYV in complex with aurachin C, 2.9 Å: 3HYX This monotopic membrane protein is thought to be buried about 12 Å in the bilayer interface. Listed under TRANSMEMBRANE PROTEINS: ALPHA-HELICAL : Oxidoreductases, MONOTOPIC MEMBRANE PROTEINS : Oxidoreductases (Monotopic).	3HYW	Data File Jmol Viewer	Marcia et al. (2009). Marcia M, Ermler U, Peng G, & Michel H (2009). The structure of Aquifex aeolicus sulfide:quinone oxidoreductase, a basis to understand sulfide detoxification and respiration. Proc Natl Acad Sci USA 106 :9625-9630. PubMed Id: 19487671.
*Sulfide:quinone oxidoreductase, selenomethionine-substituted: Homo sapiens* E Eukaryota (expressed in e. coli), 2.59 Å** native protein, 2.99 Å: 6MP5	6MO6	Data File Jmol Viewer	Jackson et al. (2019). Jackson MR, Loll PJ, & Jorns MS (2019). X-Ray Structure of Human Sulfide:Quinone Oxidoreductase: Insights into the Mechanism of Mitochondrial Hydrogen Sulfide Oxidation. Structure 27 5:794-805.e4. PubMed Id: 30905673. doi:10.1016/j.str.2019.03.002.
*Electron Transfer Flavoprotein-ubiquinone oxidoreductase (ETF-QO) with bound UQ: Sus scrofa* E Eukaryota, 2.5 Å** UQ-free structure, 2.6 Å: 2GMJ. Because this is a mitochondrial respiratory chain protein, it is listed under TRANSMEMBRANE PROTEINS: ALPHA-HELICAL : Oxidoreductases and MONOTOPIC MEMBRANE PROTEINS : Oxidoreductases (Monotopic).	2GMH	Data File Jmol Viewer	Zhang et al. (2006). Zhang J, Frerman FE, & Kim J-JP (2006). Structure of electron transfer flavoprotein-ubiquinone oxidoreductase and electron transfer to the mitochondrial ubiquinone pool. Proc Natl Acad Sci U S A 103 :16212-16217. PubMed Id: 17050691.
*mitochondrial trifunctional protein: Homo sapiens* E Eukaryota (expressed in E. coli), 3.6 Å**	6DV2	Data File Jmol Viewer	Xia et al. (2019). Xia C, Fu Z, Battaile KP, & Kim JP (2019). Crystal structure of human mitochondrial trifunctional protein, a fatty acid β-oxidation metabolon. Proc Natl Acad Sci USA 116 13:6069-6074. PubMed Id: 30850536. doi:10.1073/pnas.1816317116.
*Electron bifurcating flavoprotein Fix/EtfABCX: Thermotoga maritima* B Bacteria (expressed in Pyrococcus furiosus), 2.90 Å** cryo-EM structure	7KOE	Data File Jmol Viewer	Feng et al. (2021). Feng X, Schut GJ, Lipscomb GL, Li H, & Adams MWW (2021). Cryoelectron microscopy structure and mechanism of the membrane-associated electron-bifurcating flavoprotein Fix/EtfABCX. Proc Natl Acad Sci U S A 118 2:e2016978118. PubMed Id: 33372143. doi:10.1073/pnas.2016978118.
Dehydrogenases
*Glycerol-3-phosphate dehydrogenase (GlpD, native): Escherichia coli* B Bacteria, 1.75 Å** SeMet-GlpD, 1.95 Å: 2R4J GlpD-2-PGA, 2.3 Å: 2R45 GlpD-PEP, 2.1 Å: 2R46 GlpD-DHAP, 2.1 Å: 2R4E Listed under MONOTOPIC MEMBRANE PROTEINS : Dehydrogenases, TRANSMEMBRANE PROTEINS: ALPHA-HELICAL : Oxidoreductases.	2QCU	Data File Jmol Viewer	Yeh et al. (2008). Yeh JI, Chinte U, & Du S (2008). Structure of glycerol-3-phosphate dehydrogenase, an essential monotopic membrane enzyme involved in respiration and metabolism. Proc. Natl. Acad. Sci. USA 105 :3280-3285. PubMed Id: 18296637.
*PutA proline utilization protein: Geobacter sulfurreducens* B Bacteria (expressed in E. coli), 1.90 Å** in complex with L-tetrahydro-2-furoic acid, 2.10 Å: 4NMA in complex with L-lactate, 2.2 Å: 4NMB in complex with Zwittergent 3-12, 1.90 Å: 4NMC reduced with dithionite, 1.98 Å: 4NMD inactivated by N-propargylglycine, 2.09 Å: 4NME inactivated by N-propargylglycine and complexed with menadione bisulfite, 1.95 Å: 4NMF	4NM9	Data File Jmol Viewer	Singh et al. (2014). Singh H, Arentson BW, Becker DF, & Tanner JJ (2014). Structures of the PutA peripheral membrane flavoenzyme reveal a dynamic substrate-channeling tunnel and the quinone-binding site. Proc Natl Acad Sci USA 111 :3389-3394. PubMed Id: 24550478. doi:10.1073/pnas.1321621111.
*Ndi1 NADH Dehydrogenase: Saccharomyces cerevisiae* E Eukaryota, 2.70 Å** Ndi1-NAD⁺ complex, 2.90 Å: 4GAP Ndi1-UQ2 complex, 3.00 Å: 4GAV	4G9K	Data File Jmol Viewer	Iwata et al. (2012). Iwata M, Lee Y, Yamashita T, Yagi T, Iwata S, Cameron AD, & Maher MJ (2012). The structure of the yeast NADH dehydrogenase (Ndi1) reveals overlapping binding sites for water- and lipid-soluble substrates. Proc Natl Acad Sci USA 109 :15247-15252. PubMed Id: 22949654. doi:10.1073/pnas.1210059109 .
*Ndi1 NADH Dehydrogenase, apo form: Saccharomyces cerevisiae* E Eukaryota (expressed in E. coli), 2.39 Å** with NADH, 2.26 Å: 4G6H with Quinone, 2.48 Å: 4G74 with NAH and Quinone, 2.52 Å: 4G73	4G6G	Data File Jmol Viewer	Feng et al. (2012). Feng Y, Li W, Li J, Wang J, Ge J, Xu D, Liu Y, Wu K, Zeng Q, Wu JW, Tian C, Zhou B, & Yang M (2012). Structural insight into the type-II mitochondrial NADH dehydrogenases. Nature 491 :478-482. PubMed Id: 23086143. doi:10.1038/nature11541.
*NDH-2 NADH dehydrogenase: Caldalkalibacillus thermarum* B Bacteria (expressed in E. coli), 2.50 Å** NDH-2 is a non-proton pumping dehydrogenase.	4NWZ	Data File Jmol Viewer	Heikal et al. (2014). Heikal A, Nakatani Y, Dunn E, Weimar MR, Day CL, Baker EN, Lott JS, Sazanov LA, & Cook GM (2014). Structure of the bacterial type II NADH dehydrogenase: a monotopic membrane protein with an essential role in energy generation. Mol Microbiol 91 5:950-964. PubMed Id: 24444429. doi:10.1111/mmi.12507.
*(S)-Mandelate dehydrogenase (MDH): Pseudomonas putida* B Bacteria (expressed in E. coli), 2.2 Å**	6BFG	Data File Jmol Viewer	Sukumar et al. (2018). Sukumar N, Liu S, Li W, Mathews FS, Mitra B, & Kandavelu P (2018). Structure of the monotopic membrane protein (S)-mandelate dehydrogenase at 2.2Å resolution. Biochimie 154 :45-54. PubMed Id: 30071260. doi:10.1016/j.biochi.2018.07.017.
Decarboxylases (Monotopic)
*phosphatidylserine decarboxylase (PSD), apo-form: Escherichia coli* B Bacteria, 2.60 Å** PE-bond form, 3.60 Å: 6L07	6L06	Data File Jmol Viewer	Watanabe et al. (2020). Watanabe Y, Watanabe Y, & Watanabe S (2020). Structural Basis for Phosphatidylethanolamine Biosynthesis by Bacterial Phosphatidylserine Decarboxylase. Structure 28 7:799-809.e5. PubMed Id: 32402247. doi:10.1016/j.str.2020.04.006.
*phosphatidylserine decarboxylase (PSD) apo form: Escherichia coli* B Bacteria, 1.90 Å** apo form, 2.63 Å: 7CNX with 8PE bound, 2.12 Å: 7CNY with 10PE bound, 2.70 Å: 7CNZ	7CNW	Data File Jmol Viewer	Cho et al. (2021). Cho G, Lee E, & Kim J (2021). Structural insights into phosphatidylethanolamine formation in bacterial membrane biogenesis. Sci Rep 11 1:5785. PubMed Id: 33707636. doi:10.1038/s41598-021-85195-5.
Glycosyltransferases
*Peptidoglycan Glycosyltransferase: Staphylococcus aureus* B Bacteria, 2.8 Å** NOTE: The enzyme has a single TM segment, which is absent in the structure. The active site is external to the membrane, but the so-called Jaw Region contributes to membrane binding. 2OLV shows the enzyme complexed with moenomycin. 2OLU is the structure of the apoenzyme.	2OLV	Data File Jmol Viewer	Lovering et al. (2007). Lovering AL, de Castro LH, Lim D, & Strynadka NCJ (2007). Structural insight into the transglycosylation step in bacterial cell-wall biosynthesis. Science 315 :1402-1405. PubMed Id: 17347437.
*Peptidoglycan Glycosyltransferase penicillin-binding protein 1a (PBP1a): Aquifex aeolicus* B Bacteria (expressed in E. coli), 2.1 Å** NOTE: The enzyme has a single TM segment, which is absent in the structure. The active site is external to the membrane.	2OQO	Data File Jmol Viewer	Yuan et al. (2007). Yuan Y, Barrett D, Zhang Y, Kahne D, Sliz P, & Walker S. (2007). Crystal structure of a peptidoglycan glycosyltransferase suggests a model for processive glycan chain synthesis. Proc Natl Acad Sci USA 104 :5348-5353. PubMed Id: 17360321.
*Peptidoglycan Glycosyltransferase penicillin-binding protein 1b (PBP1b): Escherichia coli* B Bacteria, 2.16 Å** 3VMA supersedes the original PDB entry 3FWM. NOTE: The single TM segment is present in this structure. The active site is external to the membrane. SeMet Protein, 3.09 Å: 3FWL	3VMA	Data File Jmol Viewer	Sung et al. (2009). Sung MT, Lai YT, Huang CY, Chou LY, Shih HW, Cheng WC, Wong CH, & Ma C (2009). Crystal structure of the membrane-bound bifunctional transglycosylase PBP1b from Escherichia coli. Proc Natl Acad Sci USA 106 :8824-8829. PubMed Id: 19458048.
*Peptidoglycan Glycosyltransferase penicillin-binding protein 1b (PBP1b): Escherichia coli* B Bacteria, 3.28 Å** cryo-EM structure	7LQ6	Data File Jmol Viewer	Caveney et al. (2021). Caveney NA, Workman SD, Yan R, Atkinson CE, Yu Z, & Strynadka NCJ (2021). CryoEM structure of the antibacterial target PBP1b at 3.3 Å resolution. Nat Commun 12 1:2775. PubMed Id: 33986273. doi:10.1038/s41467-021-23063-6.
*Monofunctional glycosyltransferase WaaA, substrate free: Aquifex aeolicus* B Bacteria (expressed in E. coli), 2.00 Å** WaaA catalyzes the transfer of Kdo to the lipid A precursor of lipopolysaccharide. Structure with substrate, 2.42 Å: 2XCU	2XCI	Data File Jmol Viewer	Schmidt et al. (2012). Schmidt H, Hansen G, Singh S, Hanuszkiewicz A, Lindner B, Fukase K, Woodard RW, Holst O, Hilgenfeld R, Mamat U, & Mesters JR (2012). Structural and mechanistic analysis of the membrane-embedded glycosyltransferase WaaA required for lipopolysaccharide synthesis. Proc Natl Acad Sci USA 109 :6253-6258. PubMed Id: 22474366. doi:10.1073/pnas.1119894109.
*Monofunctional glycosyltransferase in complex with Lipid II analog: Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.30 Å** NOTE: The single TM segment is present in this structure. The active site is external to the membrane. Substrate-free protein, 2.52 Å: 3VMQ In complex with moenomycin, 3.69 Å: 3VMR In complex with NBD-Lipid II, 3.20 Å: 3VMS	3VMT	Data File Jmol Viewer	Huang et al. (2012). Huang CY, Shih HW, Lin LY, Tien YW, Cheng TJ, Cheng WC, Wong CH, & Ma C (2012). Crystal structure of Staphylococcus aureus transglycosylase in complex with a lipid II analog and elucidation of peptidoglycan synthesis mechanism. Proc Natl Acad Sci USA 109 :6496-6501. PubMed Id: 22493270. doi:10.1073/pnas.1203900109.
*PglH glycosyltransferase in complex with UDP-galNAc: Campylobacter jejuni* B Bacteria (expressed in E. coli), 2.3 Å** in complex w. UDP & synthetic LLO, 2.7 Å: 6EJJ in complex with UDP-CH₂-GalNAc, 3.3 Å: 6EJK	6EJI	Data File Jmol Viewer	Ramírez et al. (2018). Ramírez AS, Boilevin J, Mehdipour AR, Hummer G, Darbre T, Reymond JL, & Locher KP (2018). Structural basis of the molecular ruler mechanism of a bacterial glycosyltransferase. Nat Commun 9 1:445. PubMed Id: 29386647. doi:10.1038/s41467-018-02880-2.
GPI-Anchored Cell-Wall Proteins (GPI-CWPs) GPIs are glycosylphophatidylinositol anchors that are post-translational modifications in eukaryotes
*Dfg5 GH76 protein: Chaetomium thermophilum* E Eukaryota (expressed in E. coli), 1.05 Å** in complex with mannose, 1.30 Å: 6RY1 in complex with alpha-1,2-mannobiose, 1.30 Å: 6RY2 in complex with alpha-1,6-mannobiose, 1.30 Å: 6RY5 in complex with glucosamine, 1.30 Å: 6RY6 in complex with laminaribiose, 1.30 Å: 6RY7	6RY0	Data File Jmol Viewer	Vogt et al. (2020). Vogt MS, Schmitz GF, Varón Silva D, Mösch HU, & Essen LO (2020). Structural base for the transfer of GPI-anchored glycoproteins into fungal cell walls. Proc Natl Acad Sci USA 117 36:22061-22067. PubMed Id: 32839341. doi:10.1073/pnas.2010661117.
Phosphoglycosyl Transferases (PGT) These proteins catalyze the first membrane-committed step of glycoconjugates
*PglC phosphoglycosyl transferase, I57M/Q175M variant: Campylobacter concisus* B Bacteria (expressed in E. coli), 2.74 Å**	5W7L	Data File Jmol Viewer	Ray et al. (2018). Ray LC, Das D, Entova S, Lukose V, Lynch AJ, Imperiali B, & Allen KN (2018). Membrane association of monotopic phosphoglycosyl transferase underpins function. Nat Chem Biol 14 :538-541. PubMed Id: 29769739. doi:10.1038/s41589-018-0054-z.
Peptidases
*LepB Signal Peptidase (SPase) in complex with a β-lactam inhibitor: Escherichia coli* B Bacteria, 1.9 Å** Located in the periplasmic space, the SPase has two transmembrane segments (AAs 4-28 & 58-76), which are missing in this structure. The Ser-Lys catalytic site is part of a hydrophobic surface that interacts strongly with the membrane.	1B12	Data File Jmol Viewer	Paetzel et al. (1998). Paetzel M, Dalbey RE, & Strynadka NC (1998). Crystal structure of a bacterial signal peptidase in complex with a β-lactam inhibitor. Nature 396 :186-190. PubMed Id: 9823901.
*LepB Signal Peptidase (SPase), apoprotein: Escherichia coli* B Bacteria, 2.40 Å** Δ2-75 protein lacking the two transmembrane helices	1KN9	Data File Jmol Viewer	Paetzel et al. (2002). Paetzel M, Dalbey RE, & Strynadka NC (2002). Crystal structure of a bacterial signal peptidase apoenzyme J Biol Chem 277 :9512-9519. PubMed Id: 11741964.
*LepB Signal Peptidase (SPase) in complex with a lipopeptide inhibitor: Escherichia coli* B Bacteria, 2.47 Å** This structure of the Δ2-75 protein reveals the likely position of the signal peptide in the active site.	1T7D	Data File Jmol Viewer	Paetzel et al. (2004). Paetzel M, Goodall JJ, Kania M, Dalbey RE, & Page MG (2004). Crystallographic and biophysical analysis of a bacterial signal peptidase in complex with a lipopeptide-based inhibitor. J Biol Chem 279 :30781-30790. PubMed Id: 15136583.
*SpsB Signal Peptidase (SPase), apoprotein: Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.05 Å** in complex with peptide 1, 2.10 Å: 4WVH in complex with peptide 2, 1.90 Å: 4WVI in complex with peptide 3, 1.95 Å: 4WVJ	4WVG	Data File Jmol Viewer	Ting et al. (2016). Ting YT, Harris PW, Batot G, Brimble MA, Baker EN, & Young PG (2016). Peptide binding to a bacterial signal peptidase visualized by peptide tethering and carrier-driven crystallization. IUCrJ 3 :10-19. PubMed Id: 26870377. doi:10.1107/S2052252515019971.
*Signal Peptide Peptidase (SppA), native protein: Escherichia coli* B Bacteria, 2.55 Å** SeMet protein, 2.76 Å: 3BEZ. Long thought to be a transmembrane protein, the structure reveals a peripheral homotetramer that likely is buried in the membrane interface. Each monomer has a putative N-terminal transmembrane helix for anchoring to the membrane. This anchor was removed for crystallization. Listed under TRANSMEMBRANE PROTEINS: ALPHA-HELICAL : Intramembrane Proteases, MONOTOPIC MEMBRANE PROTEINS : Peptidases.	3BF0	Data File Jmol Viewer	Kim et al. (2008). Kim AC, Oliver DC, & Paetzel M (2008). Crystal structure of a bacterial signal Peptide peptidase. J Mol Biol 376 :352-366. PubMed Id: 18164727.
*Signal Peptide Peptidase (SppA): Bacillus subtilis* B Bacteria (expressed in E. coli), 2.37 Å** Each monomer of the homooctamer has a putative N-terminal transmembrane helix for anchoring to the membrane. This anchor was removed for crystallization. Listed under TRANSMEMBRANE PROTEINS: ALPHA-HELICAL : Intramembrane Proteases, MONOTOPIC MEMBRANE PROTEINS : Peptidases.	3RST	Data File Jmol Viewer	Nam et al. (2012). Nam SE, Kim AC, & Paetzel M (2012). Crystal Structure of Bacillus subtilis Signal Peptide Peptidase A. J Mol Biol 419 :347-358. PubMed Id: 22472423. doi:10.1016/j.jmb.2012.03.020.
*Signal Peptide Peptidase (SppA) K199A mutant showing C-terminal peptide bound in eight active sites: Bacillus subtilis* B Bacteria (expressed in E. coli), 2.39 Å** Each monomer of the homooctamer has a putative N-terminal transmembrane helix for anchoring to the membrane. This anchor was removed for crystallization. Listed under TRANSMEMBRANE PROTEINS: ALPHA-HELICAL : Intramembrane Proteases, MONOTOPIC MEMBRANE PROTEINS : Peptidases.	4KWB	Data File Jmol Viewer	Nam & Paetzel (2013). Nam SE, & Paetzel M (2013). Structure of Signal Peptide Peptidase A with C-Termini Bound in the Active Sites: Insights into Specificity, Self-Processing, and Regulation. Biochemistry 52 :8811-8822. PubMed Id: 24228759.
*Meprin β sheddase (metalloproteinase), pro-form: Homo sapiens* E Eukaryota (expressed in Trichoplusia ni), 1.85 Å** Mature form, 3.00 Å: 4GWN	4GWM	Data File Jmol Viewer	Arolas et al. (2012). Arolas JL, Broder C, Jefferson T, Guevara T, Sterchi EE, Bode W, Stöcker W, Becker-Pauly C, & Gomis-Rüth FX (2012). Structural basis for the sheddase function of human meprin β metalloproteinase at the plasma membrane. Proc Natl Acad Sci USA 109 :16131-16136. PubMed Id: 22988105. doi:10.1073/pnas.1211076109.
Cytochromes P450 P450s are members of the CYP51 family involved in sterol biosynthesis
*Lanosterol 14α-demethylase with bound lanosterol: Saccharomyces cerevisiae* E Eukaryota, 1.90 Å** with bound itraconazole, 2.19 Å: 5EQB. Supersedes 4K0F. This is the first structure of a full-length single-span 'bitopic' membrane protein. Proteins of this structural type are anchored at the membrane surface by one or two TM segments, which are generally not seen in the structures. See, for example, 1B12.	4LXJ	Data File Jmol Viewer	Monk et al. (2014). Monk BC, Tomasiak TM, Keniya MV, Huschmann FU, Tyndall JD, O'Connell JD 3rd, Cannon RD, McDonald JG, Rodriguez A, Finer-Moore JS, & Stroud RM (2014). Architecture of a single membrane spanning cytochrome P450 suggests constraints that orient the catalytic domain relative to a bilayer. Proc Natl Acad Sci USA 111 :3865-3870. PubMed Id: 24613931. doi:10.1073/pnas.1324245111.
Dihydroorotate Dehydrogenases (DHODH, class 2) Class 1 DHODHs are soluble proteins. Class 2 are membrane associated proteins.
*Dihydroorotate Dehydrogenase: Escherichia coli* B Bacteria, 1.70 Å**	1J79	Data File Jmol Viewer	Thoden et al. (2001). Thoden JB, Phillips GN Jr, Neal TM, Raushel FM, & Holden HM (2001). Molecular structure of dihydroorotase: a paradigm for catalysis through the use of a binuclear metal center. Biochemistry 40 :6989-6997. PubMed Id: 11401542.
*Dihydroorotate Dehydrogenase: Escherichia coli* B Bacteria, 1.90 Å**	1XGE	Data File Jmol Viewer	Lee et al. (2005). Lee M, Chan CW, Mitchell Guss J, Christopherson RI, & Maher MJ (2005). Dihydroorotase from Escherichia coli: loop movement and cooperativity between subunits. J Mol Biol 348 :523-533. PubMed Id: 15826651.
*Dihydroorotate Dehydrogenase in complex with atovaquone: Rattus rattus* E Eukaryota (expressed in E. coli), 2.30 Å** DHO in complex with brequinar, 2.40 Å: 1UUO	1UUM	Data File Jmol Viewer	Hansen et al. (2004). Hansen M, Le Nours J, Johansson E, Antal T, Ullrich A, Löffler M, & Larsen S (2004). Inhibitor binding in a class 2 dihydroorotate dehydrogenase causes variations in the membrane-associated N-terminal domain. Protein Sci 13 :1031-1042. PubMed Id: 15044733.
*Dihydroorotate Dehydrogenase, apo form: Homo sapiens* E Eukaryota (expressed in E. coli), 3.00 Å** DHODH in complex with brequinar analogue, 2.40 Å: 2PRH DHODH in complex with 'a novel inhibitor', 3.00 Å: 2PRL	2PRM	Data File Jmol Viewer	Walse et al. (2008). Walse B, Dufe VT, Svensson B, Fritzson I, Dahlberg L, Khairoullina A, Wellmar U, & Al-Karadaghi S (2008). The structures of human dihydroorotate dehydrogenase with and without inhibitor reveal conformational flexibility in the inhibitor and substrate binding sites. Biochemistry 47 :8929-8936. PubMed Id: 18672895.
*Dihydroorotate Dehydrogenase with triazolopyrimidine-based inhibitor DSM1: Plasmodium falciparum 3d7* E Eukaryota (expressed in E. coli), 2.00 Å** With bound triazolopyrimidine-based inhibitor DSM2, 2.40 Å: 3I68 With bound triazolopyrimidine-based inhibitor DSM74, 2.50 Å: 3I6R	3I65	Data File Jmol Viewer	Deng et al. (2009). Deng X, Gujjar R, El Mazouni F, Kaminsky W, Malmquist NA, Goldsmith EJ, Rathod PK, & Phillips MA (2009). Structural plasticity of malaria dihydroorotate dehydrogenase allows selective binding of diverse chemical scaffolds. J Biol Chem 284 :26999-27009. PubMed Id: 19640844.
Polymerases
*TagF teichoic acid polymerase: Staphylococcus epidermidis* B Bacteria (expressed in E. coli), 2.70 Å** H444N mutant, 2.81 Å: 3L7J H444N + CDPG, 15' soak, 3.10 Å: 3L7K H444N + CDPG, 30' soak, 2.95 Å: 3L7L H584A mutant, 2.85 Å: 3L7M	3L7I	Data File Jmol Viewer	Lovering et al. (2010). Lovering AL, Lin LY, Sewell EW, Spreter T, Brown ED, & Strynadka NC (2010). Structure of the bacterial teichoic acid polymerase TagF provides insights into membrane association and catalysis. Nat Struct Mol Biol 17 :582-589. PubMed Id: 20400947.
ADP-Ribosylation Factors
*ADP-ribosylation factor (ARF1), myristoylated: Saccharomyces cerevisiae* E Eukaryota (expressed in E. coli), NMR Structure**	2K5U	Data File Jmol Viewer	Liu et al. (2009). Liu Y, Kahn RA, & Prestegard JH (2009). Structure and Membrane Interaction of Myristoylated ARF1. Structure 17 :79-87. PubMed Id: 19141284.
*ADP-ribosylation factor (ARF1GTP), myristoylated: Saccharomyces cerevisiae E Eukaryota (expressed in E. coli), NMR Structure**	2KSQ	Data File Jmol Viewer	Liu et al. (2010). Liu Y, Kahn RA, & Prestegard JH (2010). Dynamic structure of membrane-anchored ArfGTP. Nature Struct Molec Biol* 17 :876-881. PubMed Id: 20601958.
Isomerases
*RPE65 visual cycle retinoid isomerase: Bos taurus* E Eukaryota, 2.14 Å** This retinal pigment epithelium (RPE) protein simultaneously cleaves and isomerizes all-trans-retinyl esters to 11-cis-retinol and a fatty acid.	3FSN	Data File Jmol Viewer	Kiser et al. (2009). Kiser PD, Golczak M, Lodowski DT, Chance MR, Palczewski K (2009). Crystal structure of native RPE65, the retinoid isomerase of the visual cycle. Proc Natl Acad Sci USA 106 :17325-17330. PubMed Id: 19805034.
*RPE65 visual cycle retinoid isomerase in a lipid matrix (crystal form C): Bos taurus* E Eukaryota, 2.50 Å** Crystal form A, 3.00 Å: 4F2Z Crystal form B, iridium derivative, 2.60 Å: 4F3A Crystal form B, native, 3.15 Å: 4F30	4F3D	Data File Jmol Viewer	Kiser et al. (2012). Kiser PD, Farquhar ER, Shi W, Sui X, Chance MR, & Palczewski K (2012). Structure of RPE65 isomerase in a lipidic matrix reveals roles for phospholipids and iron in catalysis. Proc Natl Acad Sci USA 109 :E2747-2756. PubMed Id: 23012475.
Phosphoinositide Kinases
*Phosphatidylinositol 4-kinase IIα: Homo sapiens* E Eukaryota (expressed in E. coli), 2.77 Å**	4PLA	Data File Jmol Viewer	Baumlova et al. (2014). Baumlova A, Chalupska D, Róźycki B, Jovic M, Wisniewski E, Klima M, Dubankova A, Kloer DP, Nencka R, Balla T, & Boura E (2014). The crystal structure of the phosphatidylinositol 4-kinase II?. EMBO Rep 15 :1085-1092. PubMed Id: 25168678. doi:10.15252/embr.201438841.
*Akt1 serine/threonine protein kinase: Homo sapiens* E Eukaryota (expressed in Spodoptera frugiperda), 2.05 Å**	7APJ	Data File Jmol Viewer	Truebestein et al. (2021). Truebestein L, Hornegger H, Anrather D, Hartl M, Fleming KD, Stariha JTB, Pardon E, Steyaert J, Burke JE, & Leonard TA (2021). Structure of autoinhibited Akt1 reveals mechanism of PIP₃-mediated activation. Proc Natl Acad Sci U S A 118 33:e2101496118. PubMed Id: 34385319. doi:10.1073/pnas.2101496118.
Membrane-Shaping Proteins (monotopic)
*IST1-CHMP1B ESCRT-III copolymer: Homo sapiens* E Eukaryota (expressed in E. coli), 4.00 Å** cryo-EM structure	3JC1	Data File Jmol Viewer	McCullough et al. (2015). McCullough J, Clippinger AK, Talledge N, Skowyra ML, Saunders MG, Naismith TV, Colf LA, Afonine P, Arthur C, Sundquist WI, Hanson PI, & Frost A (2015). Structure and membrane remodeling activity of ESCRT-III helical polymers. Science 350 6267:1548-1551. PubMed Id: 26634441. doi:10.1126/science.aad8305.
*ESCRT-III filament composed of CHMP1B, membrane bound: Homo sapiens* E Eukaryota (expressed in E. coli), 6.20 Å** cryo-EM structure ESCRT-III filament composed of CHMP1B+IST1 (right-handed), 3.20 Å: 6TZ4 ESCRT-III filament composed of CHMP1B+IST1 (left-handed), 3.10 Å: 6TZ5 filament composed of IST1 NTD, R16E,K27E mutant, 7.2 Å: 6TZA	6TZ9	Data File Jmol Viewer	Nguyen et al. (2020). Nguyen HC, Talledge N, McCullough J, Sharma A, Moss FR 3rd, Iwasa JH, Vershinin MD, Sundquist WI, & Frost A (2020). Membrane constriction and thinning by sequential ESCRT-III polymerization. Nat Struct Mol Biol 27 4:392-399. PubMed Id: 32251413. doi:10.1038/s41594-020-0404-x.
*CHMP2A-CHMP3 ESCRT-III copolymer, 430 Å diameter: Homo sapiens* E Eukaryota (expressed in E. coli), 3.30 Å** cryo-EM structure 410 Å diameter, 3.60 Å: 7ZCH	7ZCG	Data File Jmol Viewer	Azad et al. (2023). Azad K, Guilligay D, Boscheron C, Maity S, De Franceschi N, Sulbaran G, Effantin G, Wang H, Kleman JP, Bassereau P, Schoehn G, Roos WH, Desfosses A, & Weissenhorn W (2023). Structural basis of CHMP2A-CHMP3 ESCRT-III polymer assembly and membrane cleavage. Nat Struct Mol Biol 30 :81-90. PubMed Id: 36604498. doi:10.1038/s41594-022-00867-8.
*ESCRT-III Snf7 core domain, conformation A: Saccharomyces cerevisiae* E Eukaryota (expressed in E. coli), 2.40 Å** conformation B, 1.60 Å: 5FD9	5FD7	Data File Jmol Viewer	Tang et al. (2015). Tang S, Henne WM, Borbat PP, Buchkovich NJ, Freed JH, Mao Y, Fromme JC, & Emr SD (2015). Structural basis for activation, assembly and membrane binding of ESCRT-III Snf7 filaments. Elife 4 :e12548. PubMed Id: 26670543. doi:10.7554/eLife.12548.
*Shrub, fly ortholog of ESCRT-III SNF7/CHMP4B: Drosophila melanogaster* E Eukaryota (expressed in E. coli), 2.76 Å**	5J45	Data File Jmol Viewer	McMillan et al. (2016). McMillan BJ, Tibbe C, Jeon H, Drabek AA, Klein T, & Blacklow SC (2016). Electrostatic Interactions between Elongated Monomers Drive Filamentation of Drosophila Shrub, a Metazoan ESCRT-III Protein. Cell Rep 16 5:1211-1217. PubMed Id: 27452459. doi:10.1016/j.celrep.2016.06.093.
*Retromer Vps26-Vps29-Vps35 complex: Chaetomium thermophilum* E Eukaryota (expressed in E. coli), 11.4 Å** cryo-electron tomography with subtomogram averaging Vps29 structure by x-ray diffraction, 1.52 Å: 5W8M	6H7W	Data File Jmol Viewer	Kovtun et al. (2018). Kovtun O, Leneva N, Bykov YS, Ariotti N, Teasdale RD, Schaffer M, Engel BD, Owen DJ, Briggs JAG, & Collins BM (2018). Structure of the membrane-assembled retromer coat determined by cryo-electron tomography. Nature 561 7724:561-564. PubMed Id: 30224749. doi:10.1038/s41586-018-0526-z.
*Seipin lipid droplet-formation protein: Drosophila melanogaster* E Eukaryota (expressed in E. coli), 4 Å** cryo-EM structure	6MLU	Data File Jmol Viewer	Sui et al. (2018). Sui X, Arlt H, Brock KP, Lai ZW, DiMaio F, Marks DS, Liao M, Farese RV Jr, & Walther TC (2018). Cryo-electron microscopy structure of the lipid droplet-formation protein seipin. J Cell Biol 217 12:4080-4091. PubMed Id: 30327422. doi:10.1083/jcb.201809067.
*Seipin lipid droplet-formation protein: Saccharomyces cerevisiae* E Eukaryota, 3.45 Å** cryo-EM structure	7RSL	Data File Jmol Viewer	Arlt et al. (2022). Arlt H, Sui X, Folger B, Adams C, Chen X, Remme R, Hamprecht FA, DiMaio F, Liao M, Goodman JM, Farese RV Jr, & Walther TC (2022). Seipin forms a flexible cage at lipid droplet formation sites. Nat Struct Mol Biol 29 3:194-202. PubMed Id: 35210614. doi:10.1038/s41594-021-00718-y.
*Mgm1 mitochondrial remodeling GTPase: Chaetomium thermophilum* E Eukaryota (expressed in E. coli), 3.6 Å** by cryo-tomography: s-Mgm1 decorating the outer surface of tubulated lipid membranes, 14.7 Å: 6RZT s-Mgm1 decorating the outer surface of tubulated lipid membranes in the GTPγS bound state, 14.7 Å: 6RZU s-Mgm1 decorating the inner surface of tubulated lipid membranes, 20.6 Å: 6RZV s-Mgm1 decorating the inner surface of tubulated lipid membranes in the GTPγS bound state, 18.8 Å: 6RZW	6QL4	Data File Jmol Viewer	Faelber et al. (2019). Faelber K, Dietrich L, Noel JK, Wollweber F, Pfitzner AK, Mühleip A, Sánchez R, Kudryashev M, Chiaruttini N, Lilie H, Schlegel J, Rosenbaum E, Hessenberger M, Matthaeus C, Kunz S, von der Malsburg A, Noé F, Roux A, van der Laan M, Kühlbrandt W, & Daumke O (2019). Structure and assembly of the mitochondrial membrane remodelling GTPase Mgm1. Nature 571 7765:429-433. PubMed Id: 31292547. doi:10.1038/s41586-019-1372-3.
*Sorting nexin (SNX)-BAR Mvp1 tetramer: Saccharomyces cerevisiae* E Eukaryota (expressed in E. coli), 4.20 Å** cryo-EM structure	6Q0X	Data File Jmol Viewer	Sun et al. (2020). Sun D, Varlakhanova NV, Tornabene BA, Ramachandran R, Zhang P, & Ford MGJ (2020). The cryo-EM structure of the SNX-BAR Mvp1 tetramer. Nat Commun 11 1. PubMed Id: 32198400. doi:10.1038/s41467-020-15110-5.
*sorting nexin (SNX) protein SNX1, helical array: Mus musculus* E Eukaryota (expressed in E. coli), 9.00 Å** cryo-EM structure 10.0 Å: 7D6E	7D6D	Data File Jmol Viewer	Zhang et al. (2021). Zhang Y, Pang X, Li J, Xu J, Hsu VW, & Sun F (2021). Structural insights into membrane remodeling by SNX1. Proc Natl Acad Sci U S A 118 10. PubMed Id: 33658379. doi:10.1073/pnas.2022614118.
*ESCPE-1 membrane coat (ESCPE: endosomal SNX-BAR sorting complex for promoting exit): Homo sapiens* E Eukaryota (expressed in E. coli), 10.0 Å** cryo-EM structure x-ray: SNX1-SNX5 complex, 2.50 Å: 8A1G x-ray: SNX1-SNX5 complex, Pt derivative, 2.81 Å: 8ABQ	8AFZ	Data File Jmol Viewer	Lopez-Robles et al. (2023). Lopez-Robles C, Scaramuzza S, Astorga-Simon EN, Ishida M, Williamson CD, Baños-Mateos S, Gil-Carton D, Romero-Durana M, Vidaurrazaga A, Fernandez-Recio J, Rojas AL, Bonifacino JS, Castaño-Díez D, & Hierro A (2023). Architecture of the ESCPE-1 membrane coat. Nat Struct Mol Biol 30 7:958-969. PubMed Id: 37322239. doi:10.1038/s41594-023-01014-7.
*myelin P2 protein, N2D variant: Homo sapiens* E Eukaryota (expressed in E. coli), 1.65 Å** P2 protein is a small β-barrel protein involved in myelin sheath formation K3N mutant, 2.70 Å: 6XU9 K21Q mutant, 2.30 Å: 6XUA L27D mutantt, 2.31 Å: 6XUW R30Q mutantt, 3.00 Å: 6STS K31Q mutant, 1.80 Å: 6XVQ L35S mutant, 2.00 Å: 6XVR P38G mutant, unliganded, 1.80 Å: 6XVS K45S mutant, 2.20 Å: 4A1H K65Q mutant, 1.20 Å: 4A1Y R88Q mutant, 1.80 Å: 6XVY K112Q mutant, 1.80 Å: 4A8Z K120S mutant, 2.90 Å: 6XW9	6XU5	Data File Jmol Viewer	Ruskamo et al. (2020). Ruskamo S, Krokengen OC, Kowal J, Nieminen T, Lehtimäki M, Raasakka A, Dandey VP, Vattulainen I, Stahlberg H, & Kursula P (2020). Cryo-EM, X-ray diffraction, and atomistic simulations reveal determinants for the formation of a supramolecular myelin-like proteolipid lattice. J Biol Chem 295 26:8692-8705. PubMed Id: 32265298. doi:10.1074/jbc.RA120.013087.
*Endophilin B1 N-BAR helical scaffold protein: Homo sapiens* E Eukaryota (expressed in E. coli), 9.0 Å** cryo-EM helical scaffold, 10 Å: 6UPN	6UP6	Data File Jmol Viewer	Bhatt et al. (2021). Bhatt VS, Ashley R, & Sundborger-Lunna A (2021). Amphipathic Motifs Regulate N-BAR Protein Endophilin B1 Auto-inhibition and Drive Membrane Remodeling. Structure 29 1:61-69.e3. PubMed Id: 33086035. doi:10.1016/j.str.2020.09.012.
*coat protein complex II (COPII) on membranes, outer coat right-handed rod, class1: Saccharomyces cerevisiae* E Eukaryota (expressed in Spodoptera frugiperda), 40.0 Å** cryo-EM structure outer coat vertex, 12 Å: 6ZG6 inner coat, 4.60 Å: 6ZGA outer coat left-handed rod, 40 Å: 6ZL0	6ZG5	Data File Jmol Viewer	Hutchings et al. (2021). Hutchings J, Stancheva VG, Brown NR, Cheung ACM, Miller EA, & Zanetti G (2021). Structure of the complete, membrane-assembled COPII coat reveals a complex interaction network. Nat Commun 12 1:2034. PubMed Id: 33795673. doi:10.1038/s41467-021-22110-6.
*metazoan membrane-assembled retromer:SNX3, VPS35/VPS29 arch: Homo sapiens* E Eukaryota (expressed in E. coli), 8.90 Å** cryo-EM structure VPS26 dimer region, 9.50 Å 7BLO Grd19 complex (Chaetomium thermophilum, 9.50 Å 7BLP Grd19 complex, Vps26 dimer region, 9.20 Å 7BLQ Vps5 (SNX-BAR) complex (Chaetomium thermophilum), 9.30 Å 7BLR	7BLN	Data File Jmol Viewer	Leneva et al. (2021). Leneva N, Kovtun O, Morado DR, Briggs JAG, & Owen DJ (2021). Architecture and mechanism of metazoan retromer:SNX3 tubular coat assembly. Sci Adv 7 13:eabf8598. PubMed Id: 33762348. doi:10.1126/sciadv.abf8598.
*Atlastin-1 GTPase (residues 1-439) bound to GDP-Mg²⁺: Homo sapiens* E Eukaryota (expressed in E. coli), 2.20 Å** atlastin-3 (residues 1-334) bound to GDP-Mg²⁺, 2.10 Å 6XJO	6XJN	Data File Jmol Viewer	Kelly et al. (2021). Kelly CM, Byrnes LJ, Neela N, Sondermann H, & O'Donnell JP (2021). The hypervariable region of atlastin-1 is a site for intrinsic and extrinsic regulation. J Cell Biol 220 11:e202104128. PubMed Id: 34546351. doi:10.1083/jcb.202104128.
*caveolin-1 complex: Homo sapiens* E Eukaryota (expressed in E. coli), 3.40 Å** cryo-EM structure	7SC0	Data File Jmol Viewer	Porta et al. (2022). Porta JC, Han B, Gulsevin A, Chung JM, Peskova Y, Connolly S, Mchaourab HS, Meiler J, Karakas E, Kenworthy AK, & Ohi MD (2022). Molecular architecture of the human caveolin-1 complex. Sci Adv 8 19:eabn7232. PubMed Id: 35544577. doi:10.1126/sciadv.abn7232.
*Eps15-homology domain containing proteins (EHDs), EHD4 complex: Mus musculus* E Eukaryota (expressed in E. coli), 7.60 Å** cryo-EM structure by cryo-EM tomography	7SOX	Data File Jmol Viewer	Melo et al. (2022). Melo AA, Sprink T, Noel JK, Vázquez-Sarandeses E, van Hoorn C, Mohd S, Loerke J, Spahn CMT, & Daumke O (2022). Cryo-electron tomography reveals structural insights into the membrane remodeling mode of dynamin-like EHD filaments. Nat Commun 13 1:7641. PubMed Id: 36496453. doi:10.1038/s41467-022-35164-x.
Membrane Trafficking Proteins
*BBSome (complex of 7 Bardet–Biedl syndrome, BBS, proteins), apo form: Bos taurus* E Eukaryota, 3.44 Å** cryo-EM structure BBSome-ARL6 complex, 4.00 Å: 6VOA	6VNW	Data File Jmol Viewer	Yang et al. (2020). Yang S, Bahl K, Chou HT, Woodsmith J, Stelzl U, Walz T, & Nachury MV (2020). Near-atomic structures of the BBSome reveal the basis for BBSome activation and binding to GPCR cargoes. Elife 9 :e55954. PubMed Id: 32510327. doi:10.7554/eLife.55954.
Cell Adhesion Molecules
*Opioid Binding Protein/Cell Adhesion Molecule Like (OPCML): Homo sapiens* E Eukaryota (expressed in Trichoplusia ni), 2.65 Å**	5UV6	Data File Jmol Viewer	Birtley et al. (2019). Birtley JR, Alomary M, Zanini E, Antony J, Maben Z, Weaver GC, Von Arx C, Mura M, Marinho AT, Lu H, Morecroft EVN, Karali E, Chayen NE, Tate EW, Jurewicz M, Stern LJ, Recchi C, & Gabra H (2019). Inactivating mutations and X-ray crystal structure of the tumor suppressor OPCML reveal cancer-associated functions. Nat Commun 10 1. PubMed Id: 31316070. doi:10.1038/s41467-019-10966-8.
*P140-P110 Nap adhesion complex: Mycoplasma genitalium* B Bacteria, 4.10 Å** cryo-EM structure Adhesin P140 x-ray structure, 3.24 Å: 6S3U Heterodimer Nap Complex (P140-P110 globular) x-ray structure, 2.65 Å: 6RUT	6YRK	Data File Jmol Viewer	Aparicio et al. (2020). Aparicio D, Scheffer MP, Marcos-Silva M, Vizarraga D, Sprankel L, Ratera M, Weber MS, Seybert A, Torres-Puig S, Gonzalez-Gonzalez L, Reitz J, Querol E, Piñol J, Pich OQ, Fita I, & Frangakis AS (2020). Structure and mechanism of the Nap adhesion complex from the human pathogen Mycoplasma genitalium. Nat Commun 11 1:2877. PubMed Id: 32513917. doi:10.1038/s41467-020-16511-2.
Guanosine Triphosphatases
*Lysosomal Folliculin Complex (FLCN-FNIP2-RagA-RagC-Ragulator): Homo sapiens* E Eukaryota (expressed in S. frugiperda), 3.6 Å** cryo-EM structure	6NZD	Data File Jmol Viewer	Lawrence et al. (2019). Lawrence RE, Fromm SA, Fu Y, Yokom AL, Kim DJ, Thelen AM, Young LN, Lim CY, Samelson AJ, Hurley JH, & Zoncu R (2019). Structural mechanism of a Rag GTPase activation checkpoint by the lysosomal folliculin complex. Science 366 6468:971-977. PubMed Id: 31672913. doi:10.1126/science.aax0364.
*FLCN-FNIP2-Rag-Ragulator complex: Homo sapiens* E Eukaryota (expressed in HEK293 cells), 3.31 Å** cryo-EM structure	6ULG	Data File Jmol Viewer	Shen et al. (2019). Shen K, Rogala KB, Chou HT, Huang RK, Yu Z, & Sabatini DM (2019). Cryo-EM Structure of the Human FLCN-FNIP2-Rag-Ragulator Complex. Cell 179 6:1319-1329.e8. PubMed Id: 31704029. doi:10.1016/j.cell.2019.10.036.
Phospholipid Phosphatases
*MTMR8 catalytic phosphatase domain: Homo sapiens* E Eukaryota (expressed in E. coli), 2.8 Å**	4Y7I	Data File Jmol Viewer	Yoo et al. (2015). Yoo KY, Son JY, Lee JU, Shin W, Im DW, Kim SJ, Ryu SE, & Heo YS (2015). Structure of the catalytic phosphatase domain of MTMR8: implications for dimerization, membrane association and reversible oxidation. Acta Crystallogr. D Biol. Crystallogr. 71 :1528-1539. PubMed Id: 26143924. doi:10.1107/S139900471500927X.
*lipin/Pah phosphatidic acid phosphatase: Tetrahymena thermophila* B Bacteria (expressed in E. coli), 3 Å** Lipin Phosphatidic Acid Phosphatase with Magnesium, 3 Å: 6TZZ	6TZY	Data File Jmol Viewer	Khayyo et al. (2020). Khayyo VI, Hoffmann RM, Wang H, Bell JA, Burke JE, Reue K, & Airola MVV (2020). Crystal structure of a lipin/Pah phosphatidic acid phosphatase. Nat Commun 11 1:1309. PubMed Id: 32161260. doi:10.1038/s41467-020-15124-z.
Sorting Nexins
*sorting nexin 11 SNX11-PXe domain in dimer form: Homo sapiens* E Eukaryota (expressed in E. coli), 3.50 Å** SNX11-PXe domain in complex with PI(3,5)P₂, 2.14 Å: 6KOJ SNX11/SNX10-PXe Chimera, 2.00 Å: 6KOK	6KOI	Data File Jmol Viewer	Xu et al. (2020). Xu T, Gan Q, Wu B, Yin M, Xu J, Shu X, & Liu J (2020). Molecular Basis for PI(3,5)P₂ Recognition by SNX11, a Protein Involved in Lysosomal Degradation and Endosome Homeostasis Regulation. J Mol Biol 432 16:4750-4761. PubMed Id: 32561432. doi:10.1016/j.jmb.2020.06.010.
Pro-apoptotic BCL-2 Family
*BAK core domain BH3-groove in complex with E. coli* lipid: Homo sapiens E Eukaryota (expressed in E. coli), 2.49 Å** in complex with phosphatidylserine, 2.49 Å: 6UXN in complex with DDM, 1.80 Å: 6UXO in complex with phosphatidylglycerol, 2.49 Å: 6UXP in complex with POPC and C8E4, 1.70 Å: 6UXQ in complex with LysoPC, 1.80 Å: 6UXR	6UXM	Data File Jmol Viewer	Cowan et al. (2020). Cowan AD, Smith NA, Sandow JJ, Kapp EA, Rustam YH, Murphy JM, Brouwer JM, Bernardini JP, Roy MJ, Wardak AZ, Tan IK, Webb AI, Gulbis JM, Smith BJ, Reid GE, Dewson G, Colman PM, & Czabotar PE (2020). BAK core dimers bind lipids and can be bridged by them. Nat Struct Mol Biol 27 11:1024-1031. PubMed Id: 32929280. doi:10.1038/s41594-020-0494-5.
*Bax core dimer in bicelles: Homo sapiens* E Eukaryota (expressed in E coli), NMR structure**	6L8V	Data File Jmol Viewer	Lv et al. (2021). Lv F, Qi F, Zhang Z, Wen M, Kale J, Piai A, Du L, Wang S, Zhou L, Yang Y, Wu B, Liu Z, Del Rosario J, Pogmore J, Chou JJ, Andrews DW, Lin J, & OuYang B (2021). An amphipathic Bax core dimer forms part of the apoptotic pore wall in the mitochondrial␣membrane. EMBO J 40 14:e106438. PubMed Id: 34101209. doi:10.15252/embj.2020106438.
*Bak transmembrane helix in DPC micelles: Homo sapiens* E Eukaryota (expressed in E. coli), NMR structure** in lipid nanodiscs, 7OFO	7OFM	Data File Jmol Viewer	Sperl et al. (2021). Sperl LE, Rührnößl F, Schiller A, Haslbeck M, & Hagn F (2021). High-resolution analysis of the conformational transition of pro-apoptotic Bak at the lipid membrane. EMBO J 40 20:e107159. PubMed Id: 34523144. doi:10.15252/embj.2020107159.
Variant Surface Glycoproteins (VSG)
*N-terminal Domain of VSG2 (MITat 1.2): Trypanosoma brucei* B Bacteria, 2.90 Å**	1VSG	Data File Jmol Viewer	Freymann et al. (1990). Freymann D, Down J, Carrington M, Roditi I, Turner M, & Wiley D (1990). 2.9 Å resolution structure of the N-terminal domain of a variant surface glycoprotein from Trypanosoma brucei. J Mol Biol 216 1:141-160. PubMed Id: 2231728.
*N-terminal of VSG ILTat 1.24: Trypanosoma brucei* B Bacteria, 2.70 Å**	2VSG	Data File Jmol Viewer	Blum et al. (1993). Blum ML, Down JA, Gurnett AM, Carrington M, Turner MJ, & Wiley DC (1993). A structural motif in the variant surface glycoproteins of Trypanosoma brucei. Nature 362 6421:603-609. PubMed Id: 8464512.
*N-terminal domain of VSG M1.1: Trypanosoma brucei* B Bacteria, 1.65 Å** C-terminal domain of VSG M1.1 (NMR structure) 5M4T	5LY9	Data File Jmol Viewer	Bartossek et al. (2017). Bartossek T, Jones NG, Schäfer C, Cvitković M, Glogger M, Mott HR, Kuper J, Brennich M, Carrington M, Smith AS, Fenz S, Kisker C, & Engstler M (2017). Structural basis for the shielding function of the dynamic trypanosome variant surface glycoprotein coat. Nat Microbiol 2 11:1523-1532. PubMed Id: 28894098. doi:10.1038/s41564-017-0013-6.
*N-terminal Domain of VSG3: Trypanosoma brucei* B Bacteria, 1.41 Å**	6ELC	Data File Jmol Viewer	Pinger et al. (2018). Pinger J, Nešić D, Ali L, Aresta-Branco F, Lilic M, Chowdhury S, Kim HS, Verdi J, Raper J, Ferguson MAJ, Papavasiliou FN, & Stebbins CE (2018). African trypanosomes evade immune clearance by O-glycosylation of the VSG surface coat. Nat Microbiol 3 8:932-938. PubMed Id: 29988048. doi:10.1038/s41564-018-0187-6.
*Variant Surface Glycoproteins VSGsur & VSG13: Trypanosoma brucei* E Eukaryota, 1.21 Å** VSGsur bound to suramin, 1.86 Å 6Z7B VSGsur mutant H122A, 1.64 Å 6Z7C H122A soaked in 0.77 mM Suramin, 1.75 Å 6Z7D H122A soaked in 7.7 mM suramin, 1.66 Å 6Z7E VSG13 soaked in 0.5 M used to phase VSG13, 1.56 Å 6Z8G Variant Surface Glycoprotein VSG13, 1.38 Å 6Z8H VSGsur, I3C ("Magic Triangle") derivative, 1.92 Å 6Z79	6Z7A	Data File Jmol Viewer	Zeelen et al. (2021). Zeelen J, van Straaten M, Verdi J, Hempelmann A, Hashemi H, Perez K, Jeffrey PD, Hälg S, Wiedemar N, Mäser P, Papavasiliou FN, & Stebbins CE (2021). Structure of trypanosome coat protein VSGsur and function in suramin resistance. Nat Microbiol 6 3:392-400. PubMed Id: 33462435. doi:10.1038/s41564-020-00844-1.
TRANSMEMBRANE PROTEINS: BETA-BARREL
Adventitious Membrane Proteins: Beta-sheet Pore-forming Toxins/Attack Complexes
*α-hemolysin: Staphylococcus aureus* B Bacteria, 1.9 Å**	7AHL	Data File Jmol Viewer 7AHL alpha-hemolysin	Song et al. (1996). Song L, Hobaugh MR, Shustak C, Cheley S, Bayley H, & Gouaux JE (1996). Structure of staphylococcal a -hemolysin, a heptameric transmembrane pore. Science 274 :1859-1866. PubMed Id: 8943190.
*α-hemolysin, M113F mutant: Staphylococcus aureus* B Bacteria, 2.10 Å** M113F mutant complexed with β-cyclodextrin, 2.20 Å: 3M3R M113N mutant, 1.90 Å: 3M4D M113N mutant complexed with β-cyclodextrin, 2.30 Å: 3M4E	3M2L	Data File Jmol Viewer 3M2L 3M4E 3M3R 3M4D	Banerjee et al. (2010). Banerjee A, Mikhailova E, Cheley S, Gu LQ, Montoya M, Nagaoka Y, Gouaux E, & Bayley H (2010). Molecular bases of cyclodextrin adapter interactions with engineered protein nanopores. Proc Natl Acad Sci USA 107 :8165-8170. PubMed Id: 20400691. doi:10.1073/pnas.0914229107 .
*α-hemolysin: Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.30 Å** Crystals were prepared using 2-methyl-2,4-pentanediol without detergent.	3ANZ	Data File Jmol Viewer 3ANZ	Tanaka et al. (2011). Tanaka Y, Hirano N, Kaneko J, Kamio Y, Yao M, & Tanaka I (2011). 2-Methyl-2,4-pentanediol induces spontaneous assembly of staphylococcal α-hemolysin into heptameric pore structure. Protein Sci 20 :448-456. PubMed Id: 21280135. doi:10.1002/pro.579.
*α-hemolysin heptamer, C₁₄-bound: Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.35 Å** heptamer, H35A mutant, C₁₄-bound, 2.49 Å:: 6U4P monomer, H35A mutant, C₁₄-bound, 2.79 Å: 6U3T	6U49	Data File Jmol Viewer 6U49 6U3T 6U4P	Liu et al. (2020). Liu J, Kozhaya L, Torres VJ, Unutmaz D, & Lu M (2020). Structure-based discovery of a small-molecule inhibitor of methicillin-resistant Staphylococcus aureus virulence. J Biol Chem 295 18:5944-5959. PubMed Id: 32179646. doi:10.1074/jbc.RA120.012697.
*α-hemolysin: Vibrio campbelli* B Bacteria (expressed in E. coli), 2.00 Å** X-ray structure assembled heptamer, cryo-EM structure, 2.06 Å: 8JC7	8JBQ	Data File Jmol Viewer 8JBQ 8JC7	Chiu et al. (2023). Chiu YC, Yeh MC, Wang CH, Chen YA, Chang H, Lin HY, Ho MC, & Lin SM (2023). Structural basis for calcium-stimulating pore formation of Vibrio α-hemolysin. Nat Commun 14 1:5946. PubMed Id: 37741869. doi:10.1038/s41467-023-41579-x.
*γ-hemolysin composed of LukF and Hlg2: Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.50 Å**	3B07	Data File Jmol Viewer 3B07	Yamashita et al. (2011). Yamashita K, Kawai Y, Tanaka Y, Hirano N, Kaneko J, Tomita N, Ohta M, Kamio Y, Yao M, & Tanaka I (2011). Crystal structure of the octameric pore of staphylococcal γ-hemolysin reveals the β-barrel pore formation mechanism by two components. Proc Natl Acad Sci USA 108 :17314-17319. PubMed Id: 21969538. doi:10.1073/pnas.1110402108.
*γ-hemolysin prepore: Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.99 Å**	4P1Y	Data File Jmol Viewer 4P1Y	Yamashita et al. (2014). Yamashita D, Sugawara T, Takeshita M, Kaneko J, Kamio Y, Tanaka I, Tanaka Y, & Yao M (2014). Molecular basis of transmembrane beta-barrel formation of staphylococcal pore-forming toxins. Nat Commun 5 :4897. PubMed Id: 25263813. doi:10.1038/ncomms5897.
*LukF component of γ-hemolysin: Staphylococcus aureus* B Bacteria (expressed in E. coli), 1.9 Å** The structure is of the water soluble form of the protein. At 2.5 Å: 2LKF. With bound phosphocholine, 1.9 Å: 3LKF	1LKF	Data File Jmol Viewer 1LKF 3LKF 2LKF	Olson et al. (1999). Olson R, Nariya H, Yokota K, Kamio Y, & Gouaux E (1999). Crystal structure of Staphylococcal LukF delineates conformational changes accompanying formation of a transmembrane channel. Nature Struc. Biol 6 :134-140. PubMed Id: 10048924.
*LUK prepore formed from LukF & LukS: Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.40 Å**	4P1X	Data File Jmol Viewer 4P1X	Yamashita et al. (2014). Yamashita D, Sugawara T, Takeshita M, Kaneko J, Kamio Y, Tanaka I, Tanaka Y, & Yao M (2014). Molecular basis of transmembrane beta-barrel formation of staphylococcal pore-forming toxins. Nat Commun 5 :4897. PubMed Id: 25263813. doi:10.1038/ncomms5897.
*LukGH octamer: Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.80 Å**	4TW1	Data File Jmol Viewer 4TW1	Badarau et al. (2015). Badarau A, Rouha H, Malafa S, Logan DT, Håkansson M, Stulik L, Dolezilkova I, Teubenbacher A, Gross K, Maierhofer B, Weber S, Jägerhofer M, Hoffman D, & Nagy E (2015). Structure-function analysis of heterodimer formation, oligomerization, and receptor binding of the Staphylococcus aureus bi-component toxin LukGH. J Biol Chem 290 1:142-156. PubMed Id: 25371205. doi:10.1074/jbc.M114.598110.
*Leukocidin (LukFG) in complex with mouse CD11b I-domain (CD11b-I): Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.29 Å** in complex with human CD11b I-domain (CD11b-I), 2.75 Å: 6RHW	6RHV	Data File Jmol Viewer 6RHV 6RHW	Trstenjak et al. (2020). Trstenjak N, Milić D, Graewert MA, Rouha H, Svergun D, Djinović-Carugo K, Nagy E, & Badarau A (2020). Molecular mechanism of leukocidin GH-integrin CD11b/CD18 recognition and species specificity. Proc Natl Acad Sci USA 117 1:317-327. PubMed Id: 31852826. doi:10.1073/pnas.1913690116.
*LukD, no ligand: Staphylococcus aureus* B Bacteria (expressed in E. coli), 1.75 Å** LukD, C₁₄PC-bound, 1.5 Å: 6U2S LukF-PV, C₁₄PC-bound, 1.78 Å: 6U3F	6U33	Data File Jmol Viewer 6U33 6U3F 6U2S	Liu et al. (2020). Liu J, Kozhaya L, Torres VJ, Unutmaz D, & Lu M (2020). Structure-based discovery of a small-molecule inhibitor of methicillin-resistant Staphylococcus aureus virulence. J Biol Chem 295 18:5944-5959. PubMed Id: 32179646. doi:10.1074/jbc.RA120.012697.
*leukotoxin LukE: Staphylococcus aureus* B Bacteria (expressed in E. coli), 1.46 Å** LukE, 1.90 Å 7P8S in complex with p-cresyl sulfate, 1.60 Å 7P8U in complex with a doubly sulfated CCR2 N-terminal peptide, 1.40 Å 7P8X in complex with a sulfated ACKR1 N-terminal peptide, 1.55 Å 7P93	7P8T	Data File Jmol Viewer 7P8T 7P93 7P8S 7P8U 7P8X	Lambey et al. (2022). Lambey P, Otun O, Cong X, Hoh F, Brunel L, Verdié P, Grison CM, Peysson F, Jeannot S, Durroux T, Bechara C, Granier S, & Leyrat C (2022). Structural insights into recognition of chemokine receptors by Staphylococcus aureus leukotoxins. Elife 11 :e72555. PubMed Id: 35311641. doi:10.7554/eLife.72555.
*Panton-Valentine leukocidin (PVL) with bound C₁₄PC: Staphylococcus aureus* B Bacteria (expressed in E. coli), 2.04 Å**	6U3Y	Data File Jmol Viewer 6U3Y	Liu et al. (2020). Liu J, Kozhaya L, Torres VJ, Unutmaz D, & Lu M (2020). Structure-based discovery of a small-molecule inhibitor of methicillin-resistant Staphylococcus aureus virulence. J Biol Chem 295 18:5944-5959. PubMed Id: 32179646. doi:10.1074/jbc.RA120.012697.
*NetB Necrotic B-like enteritis toxin: Clostridium perfringens* B Bacteria (expressed in E. coli), 3.90 Å**	4H56	Data File Jmol Viewer 4H56	Savva et al. (2013). Savva CG, Fernandes da Costa SP, Bokori-Brown M, Naylor CE, Cole AR, Moss DS, Titball RW, & Basak AK (2013). Molecular architecture and functional analysis of NetB, a pore-forming toxin from Clostridium perfringens. J Biol Chem 288 5:3512-3522. PubMed Id: 23239883. doi:10.1074/jbc.M112.430223.
*Perfringolysin O (PFO) protomer: Clostridium perfringens* B Bacteria (expressed in E. coli), 2.20 Å** The protein is a thiol-activated cytolysin that uses membrane cholesterol as a receptor. 40 or more protomers assemble into a large pore anchored in the bilayer by the β-sheets of domain 4. Space group is C222₁. P2₁2₁2 space group, 3.0 Å: 1M3J. P3₁ space group, 2.90 Å: 1M3I.	1PFO	Data File Jmol Viewer 1PFO 1M3I 1M3J	Rossjohn et al. (1997). Rossjohn J, Feil SC, McKinstry WJ, Tweten RK, & Parker MW (1997). Structure of a cholesterol-binding, thiol-activated cytolysin and a model of its membrane form. Cell 89 :685-692. PubMed Id: 9182756.
*Anthrax Protective Antigen (PA) and Lethal Factor (LF) Prechannel Complex: Bacillus anthraciss* B Bacteria (expressed in E. coli), 3.10 Å** The structure is the PA₈LF₄ prechannel.	3KWV	Data File Jmol Viewer 3KWV	Feld et al. (2010). Feld GK, Thoren KL, Kintzer AF, Sterling HJ, Tang II, Greenberg SG, Williams ER, & Krantz BA (2010). Structural basis for the unfolding of anthrax lethal factor by protective antigen oligomers. Nat Struct Mol Biol 17 :1383-1390. PubMed Id: 21037566.
*Anthrax protective antigen pore: Bacillus anthracis* B Bacteria (expressed in E. coli), 2.9 Å** cryo-EM structure	3J9C	Data File Jmol Viewer 3J9C	Jiang et al. (2015). Jiang J, Pentelute BL, Collier RJ, & Zhou ZH (2015). Atomic structure of anthrax protective antigen pore elucidates toxin translocation. Nature 521 :545-549. PubMed Id: 25778700. doi:10.1038/nature14247.
*Anthrax octamer prechannel bound to full-length edema factor (EF): Bacillus anthracis* B Bacteria (expressed in E. coli), 3.30 Å** cryo-EM structure bound to full-length lethal factor (LF), 3.80 Å: 6WJJ	6VRA	Data File Jmol Viewer 6VRA 6WJJ	Zhou et al. (2020). Zhou K, Liu S, Hardenbrook NJ, Cui Y, Krantz BA, & Zhou ZH (2020). Atomic Structures of Anthrax Prechannel Bound with Full-Length Lethal and Edema Factors. Structure 28 8:879-887.e3. PubMed Id: 32521227. doi:10.1016/j.str.2020.05.009.
*Anthrax protective antigen pore translating N-terminal of LF: Bacillus anthracis* B Bacteria (expressed in E. coli), 3.30 Å** cryo-EM structure	7KXR	Data File Jmol Viewer 7KXR	Machen et al. (2021). Machen AJ, Fisher MT, & Freudenthal BD (2021). Anthrax toxin translocation complex reveals insight into the lethal factor unfolding and refolding mechanism. Sci Rep 11 1:13038. PubMed Id: 34158520. doi:10.1038/s41598-021-91596-3.
*Lymphocyte perforin monomer: Mus musculus* E Eukaryota (expressed in S. frugiperda), 2.75 Å** The multimeric pore structure has been visualized by cryo-EM.	3NSJ	Data File Jmol Viewer 3NSJ	Law et al. (2010). Law RH, Lukoyanova N, Voskoboinik I, Caradoc-Davies TT, Baran K, Dunstone MA, D'Angelo ME, Orlova EV, Coulibaly F, Verschoor S, Browne KA, Ciccone A, Kuiper MJ, Bird PI, Trapani JA, Saibil HR, & Whisstock JC (2010). The structural basis for membrane binding and pore formation by lymphocyte perforin. Nature 468 :447-451. PubMed Id: 21037563.
*Lymphocyte perforin pore: Mus musculus* E Eukaryota (expressed in Spodoptera frugiperda), 4.00 Å** cryo-EM structure	7PAG	Data File Jmol Viewer 7PAG	Ivanova et al. (2022). Ivanova ME, Lukoyanova N, Malhotra S, Topf M, Trapani JA, Voskoboinik I, & Saibil HR (2022). The pore conformation of lymphocyte perforin. Sci Adv 8 6:eabk3147. PubMed Id: 35148176. doi:10.1126/sciadv.abk3147.
*Macrophage-expressed gene 1 (MPEG1/Perforin-2), wild-type soluble pre-pore: Homo sapiens* E Eukaryota (expressed in S. frugiperda), 3.49 Å** cryo-EM structure L425K, alpha conformation pre-pore, 2.37 Å: 6U2J L425K, alpha conformation pre-pore, monomer, 2.93 Å: 6U2K L425K soluble pre-pore complex, 2.83 Å: 6U2L L425K pre-pore complex bound to liposome, 3.63 Å: 6U2W	6U23	Data File Jmol Viewer 6U23 6U2W 6U2J 6U2L 6U2K	Pang et al. (2019). Pang SS, Bayly-Jones C, Radjainia M, Spicer BA, Law RHP, Hodel AW, Parsons ES, Ekkel SM, Conroy PJ, Ramm G, Venugopal H, Bird PI, Hoogenboom BW, Voskoboinik I, Gambin Y, Sierecki E, Dunstone MA, & Whisstock JC (2019). The cryo-EM structure of the acid activatable pore-forming immune effector Macrophage-expressed gene 1. Nat Commun 10 1. PubMed Id: 31537793. doi:10.1038/s41467-019-12279-2.
*Macrophage-expressed gene 1 (MPEG1/Perforin-2), pore in ring form: Mus musculus* E Eukaryota (expressed in HEK293 cells), 3.00 Å** cryo-EM structure pore in twisted form, 4.00 Å: 8A1S	8A1D	Data File Jmol Viewer 8A1D 8A1S	Yu et al. (2022). Yu X, Ni T, Munson G, Zhang P, & Gilbert RJC (2022). Cryo-EM structures of perforin-2 in isolation and assembled on a membrane suggest a mechanism for pore formation. EMBO J 41 23:e111857. PubMed Id: 36245269. doi:10.15252/embj.2022111857.
*Cytolysin pore-forming toxin: Vibrio cholerae* B Bacteria (expressed in E. coli), 2.88 Å** Reveals the full structure of the assembled heptameric pore. The pore has a novel ring of tryptophan residues lining the narrowest constriction.	3O44	Data File Jmol Viewer 3O44	De & Olson (2011). De S & Olson R. (2011). Crystal structure of the Vibrio cholerae cytolysin heptamer reveals common features among disparate pore-forming toxins Proc Natl Acad Sci USA 108 :7385-7390. PubMed Id: 21502531. doi:10.1073/pnas.1017442108.
*Cytolysin pore-forming toxin protomer: Vibrio cholerae* B Bacteria (expressed in E. coli), 2.30 Å**	1XEZ	Data File Jmol Viewer 1XEZ	Olson & Gouaux (2005). Olson R & Gouaux E (2005). Crystal structure of the Vibrio cholerae cytolysin (VCC) pro-toxin and its assembly into a heptameric transmembrane pore J Mol Biol 350 :997-1016. PubMed Id: 15978620 . doi:10.1016/j.jmb.2005.05.045.
*Streptolysin O pore-forming toxin: Streptococcus pyogenes* B Bacteria (expressed in E. coli), 2.10 Å**	4HSC	Data File Jmol Viewer 4HSC	Feil et al. (2014). Feil SC, Ascher DB, Kuiper MJ, Tweten RK, & Parker MW (2014). Structural Studies of Streptococcus pyogenes Streptolysin O Provide Insights into the Early Steps of Membrane Penetration. J Mol Biol 426 :785-792. PubMed Id: 24316049. doi:10.1016/j.jmb.2013.11.020.
*Aerolysin pore-forming toxin Y221G mutant: Aeromonas hydrophila* B Bacteria (expressed in Aeromonas salmonicida), 2.88 Å** Y221G mutant, 2.20 Å: 3C0N Y221G mutant in complex with mannose-6-phosphate, 2.50 Å: 3C0O The paper shows models of the assembled heptameric pore.	3C0M	Data File Jmol Viewer 3C0M 3C0O 3C0N	Degiacomi et al. (2013). Degiacomi MT, Iacovache I, Pernot L, Chami M, Kudryashev M, Stahlberg H, van der Goot FG, & Dal Peraro M (2013). Molecular assembly of the aerolysin pore reveals a swirling membrane-insertion mechanism. Nat Chem Biol 9 10:623-629. PubMed Id: 23912165. doi:10.1038/nchembio.1312.
*Monalysin pore-forming toxin, cleaved form: Pseudomonas entomophila* B Bacteria (expressed in E. coli), 1.70 Å** mutant deleted of the membrane-spanning domain, 2.65 Å: 4MKQ EM structure deposited in EMBD as EMD-2698.	4MKO	Data File Jmol Viewer 4MKO 4MKQ	Leone et al. (2015). Leone P, Bebeacua C, Opota O, Kellenberger C, Klaholz B, Orlov I, Cambillau C, Lemaitre B, & Roussel A (2015). X-ray and Cryo-electron Microscopy Structures of Monalysin Pore-forming Toxin Reveal Multimerization of the Pro-form. J Biol Chem 290 :13191-13201. PubMed Id: 25847242. doi:10.1074/jbc.M115.646109.
*poly-C9 component of the complement membrane attack Complex: Homo sapiens* E Eukaryota, 8 Å** model from cryo-EM	5FMW	Data File Jmol Viewer 5FMW	Dudkina et al. (2016). Dudkina NV, Spicer BA, Reboul CF, Conroy PJ, Lukoyanova N, Elmlund H, Law RH, Ekkel SM, Kondos SC, Goode RJ, Ramm G, Whisstock JC, Saibil HR, & Dunstone MA (2016). Structure of the poly-C9 component of the complement membrane attack complex. Nat Commun 7 . PubMed Id: 26841934. doi:10.1038/ncomms10588. See also: Serna et al. (2016). Serna M, Giles JL, Morgan BP, & Bubeck D (2016). Structural basis of complement membrane attack complex formation. Nat Commun 7 :10587. PubMed Id: 26841837. doi:10.1038/ncomms10587.
*poly-C9 component of the complement membrane attack Complex: Homo sapiens* E Eukaryota (expressed in Expi293 cells), 3.9 Å** cryo-EM structure	6DLW	Data File Jmol Viewer 6DLW	Spicer et al. (2018). Spicer BA, Law RHP, Caradoc-Davies TT, Ekkel SM, Bayly-Jones C, Pang SS, Conroy PJ, Ramm G, Radjainia M, Venugopal H, Whisstock JC, & Dunstone MA (2018). The first transmembrane region of complement component-9 acts as a brake on its self-assembly. Nat Commun 9 1:3266. PubMed Id: 30111885. doi:10.1038/s41467-018-05717-0.
*Membrane attack complex (MAC) in open conformation: Homo sapiens* E Eukaryota, 5.6 Å** cryo-EM structure closed conformation, 5.6 Å: 6H04	6H03	Data File Jmol Viewer 6H03 6H04	Menny et al. (2018). Menny A, Serna M, Boyd CM, Gardner S, Joseph AP, Morgan BP, Topf M, Brooks NJ, & Bubeck D (2018). CryoEM reveals how the complement membrane attack complex ruptures lipid bilayers. Nat Commun 9 1. PubMed Id: 30552328. doi:10.1038/s41467-018-07653-5.
*3C9-sMAC Complement membrane attack complex packaged for clearance: Homo sapiens* E Eukaryota, 3.54 Å** cryo-EM structure 2C9-sMAC, 3.27 Å 7NYD	7NYC	Data File Jmol Viewer 7NYC 7NYD	Menny et al. (2021). Menny A, Lukassen MV, Couves EC, Franc V, Heck AJR, & Bubeck D (2021). Structural basis of soluble membrane attack complex packaging for clearance. Nat Commun 12 1:6086. PubMed Id: 34667172. doi:10.1038/s41467-021-26366-w.
*monomeric C9 component of the complement membrane attack Complex: Mus musculus* E Eukaryota (expressed in Expi293 cells), 2.2 Å**	6CXO	Data File Jmol Viewer 6CXO	Spicer et al. (2018). Spicer BA, Law RHP, Caradoc-Davies TT, Ekkel SM, Bayly-Jones C, Pang SS, Conroy PJ, Ramm G, Radjainia M, Venugopal H, Whisstock JC, & Dunstone MA (2018). The first transmembrane region of complement component-9 acts as a brake on its self-assembly. Nat Commun 9 1:3266. PubMed Id: 30111885. doi:10.1038/s41467-018-05717-0.
*Lysenin Pore complex: Eisenia fetida* B Bacteria (expressed in E. coli), 3.1 Å** cryo-EM structure	5GAQ	Data File Jmol Viewer 5GAQ	Bokori-Brown et al. (2016). Bokori-Brown M, Martin TG, Naylor CE, Basak AK, Titball RW, & Savva CG (2016). Cryo-EM structure of lysenin pore elucidates membrane insertion by an aerolysin family protein. Nat Commun 7 :11293. PubMed Id: 27048994. doi:10.1038/ncomms11293.
*ILY^ml Cholesterol-dependent cytolysin, CD59-responsive: Streptococcus intermedius* B Bacteria (expressed in E. coli), 2.89 Å** ILY^ml = monomer-locked via a disulfide. Bound to CD59^D22A, 2.7 Å: 5IMT	5IMW	Data File Jmol Viewer 5IMW 5IMT	Lawrence et al. (2016). Lawrence SL, Gorman MA, Feil SC, Mulhern TD, Kuiper MJ, Ratner AJ, Tweten RK, Morton CJ, & Parker MW (2016). Structural Basis for Receptor Recognition by the Human CD59-Responsive Cholesterol-Dependent Cytolysins. Structure 24 :1488-1498. PubMed Id: 27499440. doi:10.1016/j.str.2016.06.017.
*VLY^ml Cholesterol-dependent cytolysin, CD-59 responsive, bound to CD59^D22A: Gardnerella vaginalis* B Bacteria (expressed in E. coli), 2.4 Å** VLY^ml = monomer locked via a disulfide	5IMY	Data File Jmol Viewer 5IMY	Lawrence et al. (2016). Lawrence SL, Gorman MA, Feil SC, Mulhern TD, Kuiper MJ, Ratner AJ, Tweten RK, Morton CJ, & Parker MW (2016). Structural Basis for Receptor Recognition by the Human CD59-Responsive Cholesterol-Dependent Cytolysins. Structure 24 :1488-1498. PubMed Id: 27499440. doi:10.1016/j.str.2016.06.017.
*Pneumolysin (PLY) complex: Streptococcus pneumoniae* B Bacteria (expressed in E. coli), 4.5 Å** cryo-EM structure x-ray structure of PLY_D168A monomer, 2.5 Å: 5AOE x-ray structure of PLY_Δ146/147 monomer, 2.45 Å: 5AOF	5LY6	Data File Jmol Viewer 5LY6 5AOF 5AOE	van Pee et al. (2017). van Pee K, Neuhaus A, D'Imprima E, Mills DJ, Kühlbrandt W, & Yildiz Ö (2017). CryoEM structures of membrane pore and prepore complex reveal cytolytic mechanism of Pneumolysin. Elife 6 :e23644. PubMed Id: 28323617. doi:10.7554/eLife.23644.
*Epsilon toxin (Etx): Clostridium perfringens* B Bacteria (expressed in E. coli), 3.2 Å** cryo-EM structure	6RB9	Data File Jmol Viewer 6RB9	Savva et al. (2019). Savva CG, Clark AR, Naylor CE, Popoff MR, Moss DS, Basak AK, Titball RW, & Bokori-Brown M (2019). The pore structure of Clostridium perfringens epsilon toxin. Nat Commun 10 1. PubMed Id: 31201325. doi:10.1038/s41467-019-10645-8.
*Binary iota toxin complex Ib pore: Clostridium perfringens* B Bacteria (expressed in E. coli), 2.9 Å** cryo-EM structure enzymatic component (Ia) and binding component (Ib) pore with short stem, 2.8 Å: 6KLO enzymatic component (Ia) and binding component (Ib) pore with long stem, 2.9 Å: 6KLW	6KLX	Data File Jmol Viewer 6KLX 6KLW 6KLO	Yamada et al. (2020). Yamada T, Yoshida T, Kawamoto A, Mitsuoka K, Iwasaki K, & Tsuge H (2020). Cryo-EM structures reveal translocational unfolding in the clostridial binary iota toxin complex. Nat Struct Mol Biol 27 3:288-296. PubMed Id: 32123390. doi:10.1038/s41594-020-0388-6.
*binary toxin translocase CDTb in asymmetric tetradecamer conformation: Clostridioides difficile* B Bacteria (expressed in E. coli), 2.8 Å** cryo-EM structure CDTb tetradecamer in symmetric conformation, 3.1 Å: 6UWT translocase CDTb, 3.7 Å: 6UWI receptor binding domain 2 (by x-ray), 2.3 Å: 6UWO	6UWR	Data File Jmol Viewer 6UWR 6UWT 6UWO 6UWI	Xu et al. (2020). Xu X, Godoy-Ruiz R, Adipietro KA, Peralta C, Ben-Hail D, Varney KM, Cook ME, Roth BM, Wilder PT, Cleveland T, Grishaev A, Neu HM, Michel SLJ, Yu W, Beckett D, Rustandi RR, Lancaster C, Loughney JW, Kristopeit A, Christanti S, Olson JW, MacKerell AD, Georges AD, Pozharski E, & Weber DJ (2020). Structure of the cell-binding component of the Clostridium difficile binary toxin reveals a di-heptamer macromolecular assembly. Proc Natl Acad Sci USA 117 2:1049-1058. PubMed Id: 31896582. doi:10.1073/pnas.1919490117.
*binary toxin translocase CDTb with CDTa long-stem pore: Clostridioides difficile* B Bacteria (expressed in E. coli), 2.64 Å** cryo-EM structure pore with short stem, 2.56 Å: 7VNJ CDTa-bound CDTb-pore (short), 3.18 Å: 7YVQ unfolded CDTa-bound CDTb-pore (short), 2.80 Å: 7YVS	7VNN	Data File Jmol Viewer 7VNN 7VNJ 7YVQ 7YVS	Kawamoto et al. (2022). Kawamoto A, Yamada T, Yoshida T, Sato Y, Kato T, & Tsuge H (2022). Cryo-EM structures of the translocational binary toxin complex CDTa-bound CDTb-pore from Clostridioides difficile. Nat Commun 13 1:6119. PubMed Id: 36253419. doi:10.1038/s41467-022-33888-4.
De novo Designed β-barrel Membrane Proteins β-barrel Proteins Designed from First Principles
*de novo designed β-barrel TMB2.3: de novo designed* U Unclassified (expressed in E. coli), NMR structure** de novo designed TMB2.17, crystal structure, 2.07 Å: 6X9Z	6X1K	Data File Jmol Viewer 6X1K 6X9Z	Vorobieva et al. (2021). Vorobieva AA, White P, Liang B, Horne JE, Bera AK, Chow CM, Gerben S, Marx S, Kang A, Stiving AQ, Harvey SR, Marx DC, Khan GN, Fleming KG, Wysocki VH, Brockwell DJ, Tamm LK, Radford SE, & Baker D (2021). De novo design of transmembrane β barrels. Science 371 6531. PubMed Id: 33602829. doi:10.1126/science.abc8182.
Beta-Barrel Membrane Proteins: Porins and Relatives
*Porin: Rhodobacter capsulatus* B Bacteria, 1.8 Å**	2POR	Data File Jmol Viewer 2POR porin	Weiss & Schulz (1992). Weiss MS & Schulz GE (1992). Structure of porin refined at 1.8 Å resolution. J. Mol. Biol. 227 :493-509. PubMed Id: 1328651.
*Porin: Rhodopeudomonas blastica* B Bacteria, 1.96 Å**	1PRN	Data File Jmol Viewer 1PRN outer membrane porin	Kreusch & Schulz (1994). Kreusch A & Schulz GE (1994). Refined structure of the porin from Rhodopseudomonas blastica. Comparison with the porin from Rhodobacter capsulatus. J Mol Biol 243 :891-905. PubMed Id: 7525973. doi:10.1006/jmbi.1994.1690. See also: Kreusch et al. (1994). Kreusch A, Neubüser A, Schiltz E, Weckesser J, & Schulz GE (1994). Structure of the membrane channel porin from Rhodopseudomonas blastica at 2.0 Å resolution. Protein Sci 3 :58-63. PubMed Id: 8142898. doi:10.1002/pro.5560030108.
*Porin, E1M/A116K Mutant: Rhodopseudomonas blastica* B Bacteria (expressed in E. coli), 2.19 Å** E1M/E99W/A116W mutant, 1.93 Å: 2PRN E1M/A104W mutant, 1.90 Å: 3PRN E1M/Y96W/S119W mutant, 2.00 Å: 5PRN E1M/K50A/R52A mutant, 2.04 Å: 6PRN E1M/D97A/E99A mutant, 2.25 Å: 7PRN E1M/K50A/R52A/D97A/E99A mutant, 2.30 Å: 8PRN	1BH3	Data File Jmol Viewer 1BH3 5PRN 8PRN 3PRN 6PRN 2PRN 7PRN	Schmid et al. (1998). Schmid B, Maveyraud L, Krömer M, & Schulz GE (1998). Porin mutants with new channel properties. Protein Sci 7 :1603-1611. PubMed Id: 9684893. doi:10.1002/pro.5560070714.
*Porin: Rhodopseudomonas blastica* B Bacteria (expressed in E. coli), 3.00 Å** Positively charged peptide GGGGPKLAKMEKARGGGG inserted in periplasmic turn.	1H6S	Data File Jmol Viewer 1H6S	Bannwarth & Schulz (2002). Bannwarth M & Schulz GE (2002). Asymmetric conductivity of engineered porins. Protein Eng 15 :799-804. PubMed Id: 12468713. doi:10.1093/protein/15.10.799.
*OmpK36 osmoporin: Klebsiella pneumoniae* B Bacteria, 3.2 Å**	1OSM	Data File Jmol Viewer 1OSM OmpK36 osmoporin	Dutzler et al. (1999). Dutzler R, Rummel G, Alberti S, Hernandez-Alles S, Phale P, Rosenbusch J, Benedi V, & Schirmer T (1999). Crystal structure and functional characterization of OmpK36, the osmoporin of Klebsiella pneumoniae. Structure Fold. Des 7 :425-434. PubMed Id: 10196126.
*OmpK36 osmoporin, wild-type: Klebsiella pneumoniae* B Bacteria (expressed in E. coli), 1.98 Å** clinical isolate ST258, 3.23 Å: 6RCP GD insertion chimera, 2.03 Å: 6RCK	6RD3	Data File Jmol Viewer 6RD3 6RCP 6RCK	Wong et al. (2019). Wong JLC, Romano M, Kerry LE, Kwong HS, Low WW, Brett SJ, Clements A, Beis K, & Frankel G (2019). OmpK36-mediated Carbapenem resistance attenuates ST258 Klebsiella pneumoniae in vivo. Nat Commun 10 1. PubMed Id: 31477712. doi:10.1038/s41467-019-11756-y.
*OmpK36 osmoporin, native-SAD structure determined at wavelength 4.13 Å: Klebsiella pneumoniae* B Bacteria (expressed in E. coli), 2.70 Å** X-ray Structure	8PYZ	Data File Jmol Viewer 8PYZ	El Omari et al. (2023). El Omari K, Duman R, Mykhaylyk V, Orr CM, Latimer-Smith M, Winter G, Grama V, Qu F, Bountra K, Kwong HS, Romano M, Reis RI, Vogeley L, Vecchia L, Owen CD, Wittmann S, Renner M, Senda M, Matsugaki N, Kawano Y, Bowden TA, Moraes I, Grimes JM, Mancini EJ, Walsh MA, Guzzo CR, Owens RJ, Jones EY, Brown DG, Stuart DI, Beis K, & Wagner A (2023). Experimental phasing opportunities for macromolecular crystallography at very long wavelengths. Commun Chem 6 1:219. PubMed Id: 37828292. doi:10.1038/s42004-023-01014-0.
*Omp32 anion-selective porin: Comamonas acidovorans* B Bacteria, 2.1 Å**	1E54	Data File Jmol Viewer 1E54 Omp32	Zeth et al. (2000). Zeth K, Diederichs K, Welte W, & Engelhardt H (2000). Crystal structure of Omp32, the anion-selective porin from Comamonas acidovorans, in complex with a periplasmic peptide at 2.1 A resolution. Structure 8 :981-992. PubMed Id: 10986465.
*Omp32 anion-selective porin: Delftia acidovorans* B Bacteria, 1.5 Å** With bound malate, 1.45 Å: 2FGQ	2FGR	Data File Jmol Viewer 2FGR 2FGQ	Zachariae et al. (2006). Zachariae U, Kluhspies T, De S, Engelhardt H, & Zeth K (2006). High resolution crystal structures and molecular dynamics studies reveal substrate binding in the porin omp32. J Biol Chem 281 :7413-7420. PubMed Id: 16434398.
*OmpF Porin: Escherichia coli* B Bacteria, 2.4 Å** Note: Also see BtuB with bound colicin E3 R-domain, below.	2OMF	Data File Jmol Viewer 2OMF	Cowan et al. (1992). Cowan SW, Schirmer T, Rummel G, Steiert M, Ghosh R, Pauptit RA, Jansonius JN, & Rosenbusch JP (1992). Crystal structures explain functional properties of two Escherichia coli porins. Nature 358 :727-733. PubMed Id: 1380671.
*OmpF Porin from colicin-resistant E. coli: Escherichia coli* B Bacteria, 3.00 Å**	1MPF	Data File Jmol Viewer 1MPF	Jeanteur et al. (1994). Jeanteur D, Schirmer T, Fourel D, Simonet V, Rummel G, Widmer C, Rosenbusch JP, Pattus F, & Pagès JM (1994). Structural and functional alterations of a colicin-resistant mutant of OmpF porin from Escherichia coli. Proc Natl Acad Sci USA 91 :10675-10679. PubMed Id: 7524100.
*OmpF Porin: Escherichia coli* B Bacteria, 3.20 Å** Tetragonal crystal form.	1OPF	Data File Jmol Viewer 1OPF OmpF porin	Cowan et al. (1995). Cowan SW, Garavito RM, Jansonius JN, Jenkins JA, Karlsson R, König N, Pai EF, Pauptit RA, Rizkallah PJ, Rosenbusch JP, Rummel G, & Schirmer T (1995). The structure of OmpF porin in a tetragonal crystal form. Structure 3 :1041-1050. PubMed Id: 8589999. doi:10.1016/S0969-2126(01)00240-4.
*OmpF Porin, D113G mutant: Escherichia coli* B Bacteria, 3.50 Å** Deletion Mutant (Δ 109-114), 3.10 Å: 1GFN R132P Mutant, 3.30 Å: 1GFO R42C Mutant, 2.70 Å: 1GFP R82C Mutant, 2.80 Å: 1GFQ	1GFM	Data File Jmol Viewer 1GFM 1GFO 1GFQ 1GFP 1GFN	Lou et al. (1996). Lou KL, Saint N, Prilipov A, Rummel G, Benson SA, Rosenbusch JP, & Schirmer T (1996). Structural and functional characterization of OmpF porin mutants selected for larger pore size. I. Crystallographic analysis. J Biol Chem 271 :20669-20675. PubMed Id: 8702816. doi:10.1074/jbc.271.34.20669 .
*OmpF Porin, D74A mutant: Escherichia coli* B Bacteria (expressed in Escherichia coli B), 3.00 Å**	1BT9	Data File Jmol Viewer 1BT9	Phale et al. (1998). Phale PS, Philippsen A, Kiefhaber T, Koebnik R, Phale VP, Schirmer T, & Rosenbusch JP (1998). Stability of trimeric OmpF porin: the contributions of the latching loop L2. Biochemistry 37 :15663-15670. PubMed Id: 9843370. doi:10.1021/bi981215c.
*OmpF Porin, Y106F Mutant: Escherichia coli* B Bacteria, 2.20 Å** NQAAA (D113N/E117Q/R42A/R82A/R132A) Mutant, 2.40 Å: 1HXT KK (V18K/G131K) Mutant, 3.00 Å: 1HXU	1HXX	Data File Jmol Viewer 1HXX 1HXT 1HXU	Phale et al. (2001). Phale PS, Philippsen A, Widmer C, Phale VP, Rosenbusch JP, & Schirmer T (2001). Role of charged residues at the OmpF porin channel constriction probed by mutagenesis and simulation. Biochemistry 40 :6319-6325. PubMed Id: 11371193. doi:10.1021/bi010046k.
*OmpF Porin: Escherichia coli* B Bacteria, 1.6 Å** With inserted 83 residue N-terminal peptide of colicin E3, 3.0 Å: 2ZLD	2ZFG	Data File Jmol Viewer 2ZFG 2ZLD	Yamashita et al. (2008). Yamashita E, Zhalnina MV, Zakharov SD, Sharma O, & Cramer WA (2008). Crystal structures of the OmpF porin: function in a colicin translocon. EMBO J 27 :2171-2180. PubMed Id: 18636093.
*OmpF porin with a synthetic dibenzo-18-crown-6: Escherichia coli* B Bacteria, 3.40 Å**	3FYX	Data File Jmol Viewer 3FYX	Reitz et al. (2009). Reitz S, Cebi M, Reiss P, Studnik G, Linne U, Koert U, & Essen LO (2009). On the function and structure of synthetically modified porins. Angew Chem Int Ed Engl 48 :4853-4857. PubMed Id: 19322865. doi:10.1002/anie.200900457.
*OmpF Porin in complex with colicin peptide OBS1: Escherichia coli* B Bacteria, 3.01 Å** Shows colicin bound within porin lumen spanning the membrane bilayer	3O0E	Data File Jmol Viewer 3O0E	Housden et al. (2010). Housden NG, Wojdyla JA, Korczynska J, Grishkovskaya I, Kirkpatrick N, Brzozowski AM, & Kleanthous C. (2010). Directed epitope delivery across the Escherichia coli outer membrane through the porin OmpF. Proc Natl Acad Sci USA 107 :21412-21417. PubMed Id: 21098297.
*OmpF Porin: Escherichia coli* B Bacteria, 2.61 Å** Cation-selective pathway revealed by anomalous x-ray diffraction. Structure at 3.00 Å: 3HWB	3HW9	Data File Jmol Viewer 3HW9 3HWB	Dhakshnamoorthy et al. (2010). Dhakshnamoorthy B, Raychaudhury S, Blachowicz L, & Roux B (2010). Cation-selective pathway of OmpF porin revealed by anomalous X-ray diffraction. J Mol Biol 396 :293-300. PubMed Id: 19932117. doi:10.1016/j.jmb.2009.11.042.
*OmpF Porin in presence of foscholine-12: Escherichia coli* B Bacteria, 3.79 Å** Structure at 4.39 Å: 3K1B	3K19	Data File Jmol Viewer 3K19 3K1B	Kefala et al. (2010). Kefala G, Ahn C, Krupa M, Esquivies L, Maslennikov I, Kwiatkowski W, & Choe S (2010). Structures of the OmpF porin crystallized in the presence of foscholine-12. Protein Sci 19 :1117-1125. PubMed Id: 20196071. doi:10.1002/pro.369.
*OmpF porin in lipidic cubic phase: Escherichia coli* B Bacteria, 2.80 Å**	3POU	Data File Jmol Viewer 3POU	Efremov & Sazanov (2012). Efremov RG, & Sazanov LA (2012). Structure of Escherichia coli OmpF porin from lipidic mesophase. J Struct Biol 178 3:311-318. PubMed Id: 22484237. doi:10.1016/j.jsb.2012.03.005.
*OmpF Porin: Escherichia coli* B Bacteria, 3.5 Å** I2 space group	4D5U	Data File Jmol Viewer 4D5U	Chaptal et al. (2016). Chaptal V, Kilburg A, Flot D, Wiseman B, Aghajari N, Jault JM, & Falson P (2016). Two different centered monoclinic crystals of the E. coli outer-membrane protein OmpF originate from the same building block. Biochim Biophy Acta 1858 :326-332. PubMed Id: 26620074. doi:10.1016/j.bbamem.2015.11.021.
*OmpF Porin: Escherichia coli* B Bacteria, 2.54 Å** cryo-EM structure	6WTZ	Data File Jmol Viewer 6WTZ	Su et al. (2021). Su CC, Lyu M, Morgan CE, Bolla JR, Robinson CV, & Yu EW (2021). A 'Build and Retrieve' methodology to simultaneously solve cryo-EM structures of membrane proteins. Nat Methods 18 1:69-75. PubMed Id: 33408407. doi:10.1038/s41592-020-01021-2.
*OmpF and BtuB Porin in complex with colicin E9 (colE9): Escherichia coli* E Eukaryota, 4.70 Å** cryo-EM structure ColicinE9 partial translocation complex, 3.70 Å 7NST	7NSU	Data File Jmol Viewer 7NSU 7NST	Francis et al. (2021). Francis MR, Webby MN, Housden NG, Kaminska R, Elliston E, Chinthammit B, Lukoyanova N, & Kleanthous C (2021). Porin threading drives receptor disengagement and establishes active colicin transport through Escherichia coli OmpF. EMBO J 40 21:e108610. PubMed Id: 34515361. doi:10.15252/embj.2021108610.
*Omp35 (OmpF): Enterobacter aerogenes* B Bacteria (expressed in E. coli), 2.85 Å**	5O78	Data File Jmol Viewer 5O78	Acosta-Gutiérrez et al. (2018). Acosta-Gutiérrez S, Ferrara L, Pathania M, Masi M, Wang J, Bodrenko I, Zahn M, Winterhalter M, Stavenger RA, Pagès JM, Naismith JH, van den Berg B, Page MGP, & Ceccarelli M (2018). Getting Drugs into Gram-Negative Bacteria: Rational Rules for Permeation through General Porins. ACS Infect Dis 4 10:1487-1498. PubMed Id: 29962203. doi:10.1021/acsinfecdis.8b00108.
*OmpF Porin: Salmonella typhi* B Bacteria (expressed in E. coli), 2.79 Å**	3NSG	Data File Jmol Viewer 3NSG	Balasubramaniam et al. (2012). Balasubramaniam D, Arockiasamy A, Kumar PD, Sharma A, & Krishnaswamy S (2012). Asymmetric pore occupancy in crystal structure of OmpF porin from Salmonella typhi. J Struc Biol 178 :233-244. PubMed Id: 22525817. doi:10.1016/j.jsb.2012.04.005.
*OmpE35 (OmpF): Enterobacter cloacae* B Bacteria (expressed in E. coli), 2.3 Å**	6ENE	Data File Jmol Viewer 6ENE	Acosta-Gutiérrez et al. (2018). Acosta-Gutiérrez S, Ferrara L, Pathania M, Masi M, Wang J, Bodrenko I, Zahn M, Winterhalter M, Stavenger RA, Pagès JM, Naismith JH, van den Berg B, Page MGP, & Ceccarelli M (2018). Getting Drugs into Gram-Negative Bacteria: Rational Rules for Permeation through General Porins. ACS Infect Dis 4 10:1487-1498. PubMed Id: 29962203. doi:10.1021/acsinfecdis.8b00108.
*OmpK35 (OmpF): Klebsiella pneumoniae* B Bacteria (expressed in E. coli), 1.5 Å**	5O77	Data File Jmol Viewer 5O77	Acosta-Gutiérrez et al. (2018). Acosta-Gutiérrez S, Ferrara L, Pathania M, Masi M, Wang J, Bodrenko I, Zahn M, Winterhalter M, Stavenger RA, Pagès JM, Naismith JH, van den Berg B, Page MGP, & Ceccarelli M (2018). Getting Drugs into Gram-Negative Bacteria: Rational Rules for Permeation through General Porins. ACS Infect Dis 4 10:1487-1498. PubMed Id: 29962203. doi:10.1021/acsinfecdis.8b00108.
*OmpC Osmoporin: Escherichia coli* B Bacteria, 2.0 Å**	2J1N	Data File Jmol Viewer 2J1N	Baslé et al. (2006). Baslé A, Rummel G, Storici P, Rosenbusch J, & Schirmer T (2006). Crystal Structure of Osmoporin OmpC from E. coli at 2.0 Å. J Mol Biol 362 :933-942. PubMed Id: 16949612.
*OmpC Osmoporin clinical variant OmpC06: Escherichia coli* B Bacteria, 2.50 Å** Clinical variant OmpC20, 2.50 Å: 2XE2 Clinical variant OmpC26, 2.28 Å: 2XE5 Clinical variant OmpC28, 2.85 Å: 2XE3 Clinical variant OmpC33, 3.47 Å: 2XG6	2XE1	Data File Jmol Viewer 2XE1 2XE3 2XG6 2XE2 2XE5	Lou et al. (2011). Lou H, Chen M, Black SS, Bushell SR, Ceccarelli M, Mach T, Beis K, Low AS, Bamford VA, Booth IR, Bayley H, & Naismith JH (2011). Altered antibiotic transport in OmpC mutants isolated from a series of clinical strains of multi-drug resistant E. coli. PLoS One 6 :e25825. PubMed Id: 22053181. doi:10.1371/journal.pone.0025825.
*OmpC Osmoporin: Escherichia coli* B Bacteria, 2.56 Å** cryo-EM structure	7JZ3	Data File Jmol Viewer 7JZ3	Su et al. (2021). Su CC, Lyu M, Morgan CE, Bolla JR, Robinson CV, & Yu EW (2021). A 'Build and Retrieve' methodology to simultaneously solve cryo-EM structures of membrane proteins. Nat Methods 18 1:69-75. PubMed Id: 33408407. doi:10.1038/s41592-020-01021-2.
*OmpK36 (OmpC): Klebsiella pneumoniae* B Bacteria (expressed in E. coli), 1.65 Å**	5O79	Data File Jmol Viewer 5O79	Acosta-Gutiérrez et al. (2018). Acosta-Gutiérrez S, Ferrara L, Pathania M, Masi M, Wang J, Bodrenko I, Zahn M, Winterhalter M, Stavenger RA, Pagès JM, Naismith JH, van den Berg B, Page MGP, & Ceccarelli M (2018). Getting Drugs into Gram-Negative Bacteria: Rational Rules for Permeation through General Porins. ACS Infect Dis 4 10:1487-1498. PubMed Id: 29962203. doi:10.1021/acsinfecdis.8b00108.
*Omp36 (OmpC): Klebsiella aerogenes* B Bacteria (expressed in E. coli), 2.47 Å**	5O9C	Data File Jmol Viewer 5O9C	Acosta-Gutiérrez et al. (2018). Acosta-Gutiérrez S, Ferrara L, Pathania M, Masi M, Wang J, Bodrenko I, Zahn M, Winterhalter M, Stavenger RA, Pagès JM, Naismith JH, van den Berg B, Page MGP, & Ceccarelli M (2018). Getting Drugs into Gram-Negative Bacteria: Rational Rules for Permeation through General Porins. ACS Infect Dis 4 10:1487-1498. PubMed Id: 29962203. doi:10.1021/acsinfecdis.8b00108.
*OmpC homolog (OmpE36) with bound lipopolysaccharide (LPS): Enterobacter cloacae* B Bacteria (expressed in E. coli), 1.45 Å**	5FVN	Data File Jmol Viewer 5FVN	Arunmanee et al. (2016). Arunmanee W, Pathania M, Solovyova AS, Le Brun AP, Ridley H, Baslé A, van den Berg B, & Lakey JH (2016). Gram-negative trimeric porins have specific LPS binding sites that are essential for porin biogenesis. Proc Natl Acad Sci USA 113 34:E5034-E5043. PubMed Id: 27493217. doi:10.1073/pnas.1602382113.
*OmpG monomeric* porin: Escherichia coli B Bacteria, 2.3 Å**	2F1C	Data File Jmol Viewer 2F1C	Subbarao and van den Berg (2006). Subbarao GV & van den Berg B (2006). Crystal structure of the monomeric porin OmpG. J Mol Biol 360 :750-759. PubMed Id: 16797588.
*OmpG monomeric* porin in open state: Escherichia coli B Bacteria, 2.3 Å** OmpG in closed state, 2.73 Å: 2IWW	2IWV	Data File Jmol Viewer 2IWV 2IWW	Yildiz et al. (2006). Yildiz O, Vinothkumar KR, Goswami P, & Kuhlbrandt W (2006). Structure of the monomeric outer-membrane porin OmpG in the open and closed conformation. EMBO J. 25 :3702-3713. PubMed Id: 16888630.
*OmpG monomeric* porin: Escherichia coli B Bacteria, 2.18 Å** His231A/His261A mutant stable in open state	2X9K	Data File Jmol Viewer 2X9K	Korkmaz-Ozkan et al. (2010). Korkmaz-Özkan F, Köster S, Kühlbrandt W, Mäntele W, & Yildiz O (2010). Correlation between the OmpG secondary structure and its pH-dependent alterations monitored by FTIR. J Mol Biol 401 :56-67. PubMed Id: 20561532. doi:10.1016/j.jmb.2010.06.015.
*OmpG monomeric* porin: Escherichia coli B Bacteria, NMR Structure (DPC micelles)**	2JQY	Data File Jmol Viewer 2JQY	Liang & Tamm (2007). Liang B & Tamm LK (2007). Structure of outer membrane protein G by solution NMR Spectroscopy. Proc Natl Acad Sci USA 104 :16140-16145. PubMed Id: 17911261.
*OmpG monomeric* porin: Escherichia coli B Bacteria, solid-state NMR structure** protein embedded in E. coli lipid extracts	5MWV	Data File Jmol Viewer 5MWV	Retel et al. (2017). Retel JS, Nieuwkoop AJ, Hiller M, Higman VA, Barbet-Massin E, Stanek J, Andreas LB, Franks WT, van Rossum BJ, Vinothkumar KR, Handel L, de Palma GG, Bardiaux B, Pintacuda G, Emsley L, Kühlbrandt W, & Oschkinat H (2017). Structure of outer membrane protein G in lipid bilayers. Nat Commun 8 1:2073. PubMed Id: 29233991. doi:10.1038/s41467-017-02228-2.
*OmpG ΔL6-ΔD215 mutant, "quiet" porin: Escherichia coli* B Bacteria, NMR Structure**	6OQH	Data File Jmol Viewer 6OQH	Sanganna Gari et al. (2019). Sanganna Gari RR, Seelheim P, Liang B, & Tamm LK (2019). Quiet Outer Membrane Protein G (OmpG) Nanopore for Biosensing. ACS Sens 4 5:1230-1235. PubMed Id: 30990011. doi:10.1021/acssensors.8b01645.
*OmpT porin (outer membrane expressed): Vibrio cholerae* B Bacteria, 3.2 Å** in vitro folded (monomeric), 1.66 Å: 6EHD in vitro folded (trimeric), 2.72 Å: 6EHF OmpTΔL8, 2.31 Å: 6EHE	5OYK	Data File Jmol Viewer 5OYK 6EHD 6EHF 6EHE	Pathania et al. (2018). Pathania M, Acosta-Gutierrez S, Bhamidimarri SP, Baslé A, Winterhalter M, Ceccarelli M, & van den Berg B (2018). Unusual Constriction Zones in the Major Porins OmpU and OmpT from Vibrio cholerae. Structure 26 5:708-721.e4. PubMed Id: 29657131. doi:10.1016/j.str.2018.03.010.
*OmpU: Vibrio cholerae* B Bacteria (expressed in E. coli), 2.22 Å**	5ONU	Data File Jmol Viewer 5ONU	Li et al. (2018). Li H, Zhang W, & Dong C (2018). Crystal structure of the outer membrane protein OmpU from Vibrio cholerae at 2.2 Å resolution. Acta Crystallogr D Struct Biol 74 :21-29. PubMed Id: 29372896. doi:10.1107/S2059798317017697.
*OmpU porin: Vibrio cholerae* B Bacteria (expressed in E. coli), 1.55 Å** OmpU ΔN, 2.02 Å: 6EHC	6EHB	Data File Jmol Viewer 6EHB 6EHC	Pathania et al. (2018). Pathania M, Acosta-Gutierrez S, Bhamidimarri SP, Baslé A, Winterhalter M, Ceccarelli M, & van den Berg B (2018). Unusual Constriction Zones in the Major Porins OmpU and OmpT from Vibrio cholerae. Structure 26 5:708-721.e4. PubMed Id: 29657131. doi:10.1016/j.str.2018.03.010.
*PhoE: Escherichia coli* B Bacteria, 3.0 Å**	1PHO	Data File Jmol Viewer 1PHO PhoE phosphoporin	Cowan et al. (1992). Cowan SW, Schirmer T, Rummel G, Steiert M, Ghosh R, Pauptit RA, Jansonius JN, & Rosenbusch JP (1992). Crystal structures explain functional properties of two Escherichia coli porins. Nature 358 :727-733. PubMed Id: 1380671.
*LamB Maltoporin: Salmonella typhimurium* B Bacteria, 2.4 Å**	2MPR	Data File Jmol Viewer 2MPR maltoporin	Meyer et al. (1997). Meyer JEW, Hofnung M, & Schulz GE (1997). Structure of maltoporin from Salmonella typhimurium ligated with a nitrophenyl-maltotrioside. J. Mol. Biol 266 :761-775. PubMed Id: 9102468.
*LamB Maltoporin: Escherichia coli* B Bacteria, 3.1 Å**	1MAL	Data File Jmol Viewer 1MAL maltoporin	Schirmer et al. (1995). Schirmer T, Keller TA, Wang YF, & Rosenbusch JP (1995). Structural basis for sugar translocation through maltoporin channels at 3.1 Å resolution. Science 267 :512-4. PubMed Id: 7824948.
*LamB Maltoporin in complex with maltose: Escherichia coli* B Bacteria, 2.6 Å** In complex with maltotriose, 3.20 Å: 1MPN In complex with maltohexaose, 2.80 Å: 1MPO	1MPM	Data File Jmol Viewer 1MPM 1MPO 1MPN	Dutzler et al. (1996). Dutzler R, Wang YF, Rizkallah P, Rosenbusch JP, Schirmer T (1996). Crystal structures of various maltooligosaccharides bound to maltoporin reveal a specific sugar translocation pathway. Structure 4 :127-134. PubMed Id: 8805519.
*LamB Maltoporin in complex with sucrose: Escherichia coli* B Bacteria, 2.4 Å** In complex with trehalose, 3.0 Å: 1MPQ	1AF6	Data File Jmol Viewer 1AF6 1MPQ	Wang et al. (1997). Wang YF, Dutzler R, Rizkallah PJ, Rosenbusch JP, & Schirmer T (1997). Channel specificity: structural basis for sugar discrimination and differential flux rates in maltoporin. J Mol Biol 272 :56-63. PubMed Id: 9299337.
*ScrY sucrose-specific porin: Salmonella typhimurium* B Bacteria, 2.4 Å** Complexed Form, 1A0T. Uncomplexed form, 1A0S.	1A0T	Data File Jmol Viewer 1A0T 1A0S porin scrY, sucrose-specific	Forst et al. (1998). Forst D, Welte W, Wacker T, & Diederichs K (1998). Structure of the sucrose-specific porin ScrY from Salmonella typhimurium and its complex with sucrose. Nature Structural Biol 5 :37-46. PubMed Id: 9437428.
*MspA mycobacterial porin: Mycobacterium smegmatis* B Bacteria, 2.5 Å** Homooctamer	1UUN	Data File Jmol Viewer 1UUN MspA	Faller et al. (2004). Faller M, Niederweis M, & Schulz GE (2004). The structure of a mycobacterial outer-membrane channel. Science 303 :1189-1192. PubMed Id: 14976314.
*OprB carbohydrate-specific transporter at high pH: Pseudomonas putida* B Bacteria (expressed in E. coli), 2.70 Å** low-pH structure, 3.10 Å: 4GF4	4GEY	Data File Jmol Viewer 4GEY 4GF4	van den Berg (2012). van den Berg B (2012). Structural basis for outer membrane sugar uptake in pseudomonads. J Biol Chem 287 :41044-41052. PubMed Id: 23066028. doi:10.1074/jbc.M112.408518.
*OprO diphosphate-specific transporter: Pseudomonas aeruginosa* B Bacteria, 1.52 Å** F62Y/D114Y mutant, 1.54 Å: 4RJX	4RJW	Data File Jmol Viewer 4RJW 4RJX	Modi et al. (2015). Modi N, Ganguly S, Bárcena-Uribarri I, Benz R, van den Berg B, & Kleinekathöfer U (2015). Structure, Dynamics, and Substrate Specificity of the OprO Porin from Pseudomonas aeruginosa. Biophys J 109 :1429-1438. PubMed Id: 26445443. doi:10.1016/j.bpj.2015.07.035.
*OprP phosphate-specific transporter: Pseudomonas aeruginosa* B Bacteria, 1.9 Å** Contains a novel nine-residue arginine ladder	2O4V	Data File Jmol Viewer 2O4V OprP	Moraes et al. (2007). Moraes TF, Bains M, Hancock REW & Strynadka NCJ (2007). An arginine ladder in OprP mediates phosphate-specific transfer across the outer membrane. Nature Struc Mol Biol 14 :85-87. PubMed Id: 17187075.
*PorB outer membrane protein, native structure: Neisseria meningitidis* B Bacteria (expressed in E. coli), 2.30 Å** The second most common OMP of Neisseria, PorB is required for pathogenesis. Former 3A2R, 3A2T, and 3A2U superseded by 3VZT, 3VZW, and 3VZU, respectively. In complex with sucrose, 2.20 Å: 3A2S In complex with galactose, 3.20 Å: 3VZW In complex with AMP-PNP, 2.90 Å: 3ZVU	3VZT	Data File Jmol Viewer 3VZT 3VZU 3A2S 3VZW	Tanabe et al. (2010). Tanabe M, Nimigean CM, & Iverson TM (2010). Structural basis for solute transport, nucleotide regulation, and immunological recognition of Neisseria meningitidis PorB. Proc Natl Acad Sci USA 107 :6811-6816. PubMed Id: 20351243.
*PorB outer membrane protein: Neisseria meningitidis* B Bacteria (expressed in E. coli), 3.32 Å** Loop 7 mutant, 2.40 Å: 3WI5	3WI4	Data File Jmol Viewer 3WI4 3WI5	Kattner et al. (2014). Kattner C, Toussi DN, Zaucha J, Wetzler LM, Rüppel N, Zachariae U, Massari P, & Tanabe M (2014). Crystallographic analysis of Neisseria meningitidis PorB extracellular loops potentially implicated in TLR2 recognition. J Struct Biol 185 3:440-447. PubMed Id: 24361688. doi:10.1016/j.jsb.2013.12.006.
*PorB outer membrane protein, G103K mutant: Neisseria meningitidis* B Bacteria (expressed in E. coli), 2.76 Å**	7DE8	Data File Jmol Viewer 7DE8	Bartsch et al. (2021). Bartsch A, Ives CM, Kattner C, Pein F, Diehn M, Tanabe M, Munk A, Zachariae U, Steinem C, & Llabrás S (2021). An antibiotic-resistance conferring mutation in a neisserial porin: Structure, ion flux, and ampicillin binding. Biochim Biophys Acta Biomembr 1863 6:183601. PubMed Id: 33675718. doi:10.1016/j.bbamem.2021.183601.
*PorB outer membrane protein: Neisseria gonorrhoeae* B Bacteria, 3.20 Å**	4AUI	Data File Jmol Viewer 4AUI	Zeth et al. (2013). Zeth K, Kozjak-Pavlovic V, Faulstich M, Fraunholz M, Hurwitz R, Kepp O, & Rudel T (2013). Structure and function of the PorB porin from disseminating Neisseria gonorrhoeae. Biochem J 449 3:631-642. PubMed Id: 23095086. doi:10.1042/BJ20121025.
*KdgM monomeric* porin in complex with disordered oligogalacturonate, wild-type: Dickeya dadantii B Bacteria (expressed in E. coli), 2.10 Å** K161S mutant in complex with disordered oligogalacturonate, 2.10 Å: 4PR7	4FQE	Data File Jmol Viewer 4FQE 4PR7	Hutter et al. (2014). Hutter CA, Lehner R, Wirth Ch, Condemine G, Peneff C, & Schirmer T (2014). Structure of the oligogalacturonate-specific KdgM porin. Acta Crystallogr. D Biol. Crystallogr. 70 :1770-1778. PubMed Id: 24914987. doi:10.1107/S1399004714007147.
*CymA monomeric outer membrane protein (NHis-SeMet): Klebsiella oxytoca* B Bacteria (expressed in E. coli), 2.51 Å** NHis-native, 1.83 Å: 4V3H wild-type, 2.30 Å: 4D51 &alfa;-cyclodextrin soak, 1.70 Å: 4D5B β-cyclodextrin soak, 1.90 Å: 4D5D	4V3G	Data File Jmol Viewer 4V3G 4D5D 4D51 4D5B 4V3H	van den Berg et al. (2015). van den Berg B, Prathyusha Bhamidimarri S, Dahyabhai Prajapati J, Kleinekathöfer U, & Winterhalter M (2015). Outer-membrane translocation of bulky small molecules by passive diffusion. Proc Natl Acad Sci USA 112 :E2991-E2999. PubMed Id: 26015567. doi:10.1073/pnas.1424835112.
*COG4313 outer membrane channel: Pseudomonas putida* B Bacteria (expressed in E. coli), 2.30 Å**	4RL8	Data File Jmol Viewer 4RL8	van den Berg et al. (2015). van den Berg B, Bhamidimarri SP, & Winterhalter M (2015). Crystal structure of a COG4313 outer membrane channel. Sci Rep 5 :11927. PubMed Id: 26149193. doi:10.1038/srep11927.
*OprG outer membrane amino acid transporter: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), NMR structure** P92A mutant, NMR structure: 2N6P	2N6L	Data File Jmol Viewer 2N6L 2N6P	Kucharska et al. (2015). Kucharska I, Seelheim P, Edrington T, Liang B, & Tamm LK (2015). OprG Harnesses the Dynamics of its Extracellular Loops to Transport Small Amino Acids across the Outer Membrane of Pseudomonas aeruginosa. Structure 23 :2234-2245. PubMed Id: 26655471. doi:10.1016/j.str.2015.10.009.
*MOMP major outer membrane protein: Campylobacter jejuni* (expressed in E. coli), 2.1 Å** expressed in C. jejuni, 2.88 Å: 5LDT	5LDV	Data File Jmol Viewer 5LDV 5LDT	Ferrara et al. (2016). Ferrara LG, Wallat GD, Moynié L, Dhanasekar NN, Aliouane S, Acosta-Gutiérrez S, Pagès JM, Bolla JM, Winterhalter M, Ceccarelli M, & Naismith JH (2016). MOMP from Campylobacter jejuni Is a Trimer of 18-Stranded β-Barrel Monomers with a Ca²⁺ Ion Bound at the Constriction Zone. J Mol Biol 428 :4528-4543. PubMed Id: 27693650. doi:10.1016/j.jmb.2016.09.021.
*Omp-Pst1 type-A porin: Providencia stuartii* B Bacteria (expressed in E. coli), 3.2 Å** Structures reveal that these porins can self-associate to form dimers of trimers Omp-Pst1 type-B, 2.7 Å: 5NXR Omp-Pst1 type-B in complex with maltose, 3 Å: 5NXU Omp-Pst2 reveals dimer of trimers, 2.2 Å: 4D65 283-LGNY-286, steric zipper that supports dimerization of Pst2, 0.997 Å: 5N9H 206-GVVTSE-211 steric zipper that supports dimerization of Pst1, 1.91 Å: 5N9I Pst1 L5 deletion, 3.12 Å: 5NXN	4D64	Data File Jmol Viewer 4D64 4D65 5N9I 5N9H 5NXU 5NXR 5NXN	El-Khatib et al. (2018). El-Khatib M, Nasrallah C, Lopes J, Tran QT, Tetreau G, Basbous H, Fenel D, Gallet B, Lethier M, Bolla JM, Pagès JM, Vivaudou M, Weik M, Winterhalter M, & Colletier JP (2018). Porin self-association enables cell-to-cell contact inProvidencia stuartiifloating communities. Proc Natl Acad Sci USA 115 10:E2220-E2228. PubMed Id: 29476011. doi:10.1073/pnas.1714582115.
*Chitoporin (ChiP), in vitro-folded crystal form I: Vibrio harveyi* B Bacteria (expressed in E. coli), 1.95 Å** in vitro-folded crystal form II, 3.08 Å: 5MDP outer membrane (OM) expressed ChiP, 2.5 Å: 5MDQ with chito-hexose, in vitro-folded 1.9 Å: 5MDR with chito-tetraose OM-expressed, 2.6 Å:5MDS	5MDO	Data File Jmol Viewer 5MDO 5MDP 5MDQ 5MDR 5MDS	Aunkham et al. (2018). Aunkham A, Zahn M, Kesireddy A, Pothula KR, Schulte A, Baslá A, Kleinekathöfer U, Suginta W, & van den Berg B (2018). Structural basis for chitin acquisition by marine Vibrio species. Nat Commun 9 1. PubMed Id: 29335469. doi:10.1038/s41467-017-02523-y.
*FapF amyloid secretion protein FapF_β: Pseudomonas sp. UK4* B Bacteria (expressed in E. coli), 2.5 Å** engineered protein, residues 83-406 (N-terminal domain and following disordered linker removed) F103A mutant, 2.84 Å: 5O67 R157A mutant, 3.08 Å: 5O68	5O65	Data File Jmol Viewer 5O65 5O68 5O67	Rouse et al. (2017). Rouse SL, Hawthorne WJ, Berry JL, Chorev DS, Ionescu SA, Lambert S, Stylianou F, Ewert W, Mackie U, Morgan RML, Otzen D, Herbst FA, Nielsen PH, Dueholm M, Bayley H, Robinson CV, Hare S, & Matthews S (2017). A new class of hybrid secretion system is employed in Pseudomonas amyloid biogenesis. Nat Commun 8 1. PubMed Id: 28811582. doi:10.1038/s41467-017-00361-6.
*DcaP outer membrane channel: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 2.2 Å**	6EUS	Data File Jmol Viewer 6EUS	Bhamidimarri et al. (2019). Bhamidimarri SP, Zahn M, Prajapati JD, Schleberger C, Söderholm S, Hoover J, West J, Kleinekathöfer U, Bumann D, Winterhalter M, & van den Berg B (2019). A Multidisciplinary Approach toward Identification of Antibiotic Scaffolds for Acinetobacter baumannii. Structure 27 2:268-280.e6. PubMed Id: 30554842. doi:10.1016/j.str.2018.10.021.
*MtrAB electron transporter complex: Shewanella baltica* B Bacteria (expressed in Shewanella oneidensis), 2.70 Å** MtrC, 2.29 Å: 6QYC	6R2Q	Data File Jmol Viewer 6R2Q 6QYC	Edwards et al. (2020). Edwards MJ, White GF, Butt JN, Richardson DJ, & Clarke TA (2020). The Crystal Structure of a Biological Insulated Transmembrane Molecular Wire. Cell 181 3:665-673.e10. PubMed Id: 32289252. doi:10.1016/j.cell.2020.03.032.
Outer Membrane Carboxylate Channels (Occ) These outer membrane proteins require substrates to have a carboxyl group for efficient transport. OccD channels are selective for basic amino acids. OccK channels prefer cyclic substrates. See Eren et al. (2012).
*OccD1 (OprD) basic amino acid uptake channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.9 Å**	2ODJ	Data File Jmol Viewer 2ODJ	Biswas et al. (2007). Biswas S, Mohammad MM, Patel DR, Movileanu L, & van den Berg B (2007). Structural insight into OprD substrate specificity. Nature Struct Mol Biol 14 :1108-1109. PubMed Id: 17952093.
*OccD1 (OprD) basic amino acid uptake channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.15 Å**	3SY7	Data File Jmol Viewer 3SY7	Eren et al. (2012). Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, & van den Berg B (2012). Substrate Specificity within a Family of Outer Membrane Carboxylate Channels. PLoS Biol 10 :e1001242. PubMed Id: 22272184. doi:10.1371/journal.pbio.1001242.
*OccD2 (OpdC) basic amino acid uptake channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.80 Å**	3SY9	Data File Jmol Viewer 3SY9	Eren et al. (2012). Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, & van den Berg B (2012). Substrate Specificity within a Family of Outer Membrane Carboxylate Channels. PLoS Biol 10 :e1001242. PubMed Id: 22272184. doi:10.1371/journal.pbio.1001242.
*OccD3 (OpdP) basic amino acid uptake channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.70 Å**	3SYB	Data File Jmol Viewer 3SYB	Eren et al. (2012). Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, & van den Berg B (2012). Substrate Specificity within a Family of Outer Membrane Carboxylate Channels. PLoS Biol 10 :e1001242. PubMed Id: 22272184. doi:10.1371/journal.pbio.1001242.
*OccK1 (OpdK) benzoate channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.8 Å** Binds vanillate. Forms labile trimer.	2QTK	Data File Jmol Viewer 2QTK	Biswas et al. (2008). Biswas S, Mohammad MM, Movileanu L, & van den Berg B (2008). Crystal structure of the outer membrane protein OpdK from Pseudomonas aeruginosa. Structure 16 :1027-1035. PubMed Id: 18611376.
*OccK1 (OpdK) benzoate channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 1.65 Å**	3SYS	Data File Jmol Viewer 3SYS	Eren et al. (2012). Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, & van den Berg B (2012). Substrate Specificity within a Family of Outer Membrane Carboxylate Channels. PLoS Biol 10 :e1001242. PubMed Id: 22272184. doi:10.1371/journal.pbio.1001242.
*OccK2 (OpdF) glucuronate channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.30 Å**	3SZD	Data File Jmol Viewer 3SZD	Eren et al. (2012). Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, & van den Berg B (2012). Substrate Specificity within a Family of Outer Membrane Carboxylate Channels. PLoS Biol 10 :e1001242. PubMed Id: 22272184. doi:10.1371/journal.pbio.1001242.
*OccK3 (OpdO) aromatic hydrocarbon channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 1.45 Å**	3SZV	Data File Jmol Viewer 3SZV	Eren et al. (2012). Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, & van den Berg B (2012). Substrate Specificity within a Family of Outer Membrane Carboxylate Channels. PLoS Biol 10 :e1001242. PubMed Id: 22272184. doi:10.1371/journal.pbio.1001242.
*OccK4 (OpdL) aromatic hydrocarbon channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.10 Å**	3T0S	Data File Jmol Viewer 3T0S	Eren et al. (2012). Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, & van den Berg B (2012). Substrate Specificity within a Family of Outer Membrane Carboxylate Channels. PLoS Biol 10 :e1001242. PubMed Id: 22272184. doi:10.1371/journal.pbio.1001242.
*OccK5 (OpdH) aromatic hydrocarbon channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.60 Å**	3T20	Data File Jmol Viewer 3T20	Eren et al. (2012). Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, & van den Berg B (2012). Substrate Specificity within a Family of Outer Membrane Carboxylate Channels. PLoS Biol 10 :e1001242. PubMed Id: 22272184. doi:10.1371/journal.pbio.1001242.
*OccK6 (OpdQ) aromatic hydrocarbon channel: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.35 Å**	3T24	Data File Jmol Viewer 3T24	Eren et al. (2012). Eren E, Vijayaraghavan J, Liu J, Cheneke BR, Touw DS, Lepore BW, Indic M, Movileanu L, & van den Berg B (2012). Substrate Specificity within a Family of Outer Membrane Carboxylate Channels. PLoS Biol 10 :e1001242. PubMed Id: 22272184. doi:10.1371/journal.pbio.1001242.
*BenF-like Porin (putative) benzoate channel: Pseudomonas fluorescens* B Bacteria, 2.60 Å** Probably belongs to OccK subfamily	3JTY	Data File Jmol Viewer 3JTY	Sampathkumar et al. (2010). Sampathkumar P, Lu F, Zhao X, Li Z, Gilmore J, Bain K, Rutter ME, Gheyi T, Schwinn KD, Bonanno JB, Pieper U, Fajardo JE, Fiser A, Almo SC, Swaminathan S, Chance MR, Baker D, Atwell S, Thompson DA, Emtage JS, Wasserman SR, Sali A, Sauder JM, &Burley SK (2010). Structure of a putative BenF-like porin from Pseudomonas fluorescens Pf-5 at 2.6 Å resolution. Proteins 78 :3056-3062. PubMed Id: 20737437.
*OccAB1 outer membrane channel: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 2.05 Å**	5DL5	Data File Jmol Viewer 5DL5	Zahn et al. (2016). Zahn M, Bhamidimarri SP, Baslé A, Winterhalter M, & van den Berg B (2016). Structural Insights into Outer Membrane Permeability of Acinetobacter baumannii. Structure 24 :221-231. PubMed Id: 26805524. doi:10.1016/j.str.2015.12.009.
*OccAB2 outer membrane channel: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 2.9 Å**	5DL6	Data File Jmol Viewer 5DL6	Zahn et al. (2016). Zahn M, Bhamidimarri SP, Baslé A, Winterhalter M, & van den Berg B (2016). Structural Insights into Outer Membrane Permeability of Acinetobacter baumannii. Structure 24 :221-231. PubMed Id: 26805524. doi:10.1016/j.str.2015.12.009.
*OccAB3 outer membrane channel: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 1.75 Å**	5DL7	Data File Jmol Viewer 5DL7	Zahn et al. (2016). Zahn M, Bhamidimarri SP, Baslé A, Winterhalter M, & van den Berg B (2016). Structural Insights into Outer Membrane Permeability of Acinetobacter baumannii. Structure 24 :221-231. PubMed Id: 26805524. doi:10.1016/j.str.2015.12.009.
*OccAB4 outer membrane channel: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 2.2 Å**	5DL8	Data File Jmol Viewer 5DL8	Zahn et al. (2016). Zahn M, Bhamidimarri SP, Baslé A, Winterhalter M, & van den Berg B (2016). Structural Insights into Outer Membrane Permeability of Acinetobacter baumannii. Structure 24 :221-231. PubMed Id: 26805524. doi:10.1016/j.str.2015.12.009.
Beta-Barrel Membrane Proteins: Monomeric/Dimeric
*TolC outer membrane protein: Escherichia coli* B Bacteria, 2.1 Å** NOTE: Functional protein is a homotrimer. Each monomer contributes 4 strands to a single barrel.	1EK9	Data File Jmol Viewer 1EK9 outer membrane protein TolC	Koronakis et al. (2000). Koronakis V, Sharff A, Koronakis E, Luisi B, & Hughes C (2000). Crystal structure of the bacterial membrane protein TolC central to multidrug efflux and protein export. Nature 405 :914-919. PubMed Id: 10879525.
*TolC outer membrane protein, ligand blocked: Escherichia coli* B Bacteria, 2.75 Å**	1TQQ	Data File Jmol Viewer 1TQQ	Higgins et al. (2004). Higgins MK, Eswaran J, Edwards P, Schertler GF, Hughes C, & Koronakis V (2004). Structure of the ligand-blocked periplasmic entrance of the bacterial multidrug efflux protein TolC. J Mol Biol 342 :697-702. PubMed Id: 15342230.
*TolC outer membrane protein (Y362F, R367E), partially open state: Escherichia coli* B Bacteria, 3.2 Å** 2VDE is P2₁2₁2₁ form. C2 form, 3.30 Å: 2VDD	2VDE	Data File Jmol Viewer 2VDE 2VDD	Bavro et al. (2008). Bavro VN, Pietras Z, Furnham N, Pérez-Cano L, Fernández-Recio J, Pei XY, Misra R, & Luisi B (2008). Assembly and channel opening in a bacterial drug efflux machine. Mol Cell 30 :114-121. PubMed Id: 18406332.
*TolC outer membrane protein in a nanodisc with colicin E1 fragment: Escherichia coli* B Bacteria, 3.09 Å** cryo-EM structure TolC alone, 2.84 Å 6WXI	6WXH	Data File Jmol Viewer 6WXH 6WXI	Budiardjo et al. (2022). Budiardjo SJ, Stevens JJ, Calkins AL, Ikujuni AP, Wimalasena VK, Firlar E, Case DA, Biteen JS, Kaelber JT, & Slusky JSG (2022). Colicin E1 opens its hinge to plug TolC. Elife 11 :e73297. PubMed Id: 35199644. doi:10.7554/eLife.73297.
*TolC outer membrane protein in complex with KlebC: Klebsiella quasipneumoniae* B Bacteria (expressed in E. coli), 3.20 Å** cryo-EM structure Trimeric efflux pump alone, 3.30 Å 7NG9 x-ray structure: KlebC, 1.90 Å 7NNA	7NG8	Data File Jmol Viewer 7NG8 7NG9 7NNA	Housden et al. (2021). Housden NG, Webby MN, Lowe ED, El-Baba TJ, Kaminska R, Redfield C, Robinson CV, & Kleanthous C (2021). Toxin import through the antibiotic efflux channel TolC. Nat Commun 12 1:4625. PubMed Id: 34330923. doi:10.1038/s41467-021-24930-y.
*CmeC bacterial multi-drug efflux transporter outer membrane channel: Campylobacter jejuni* B Bacteria, 2.37 Å**	4MT4	Data File Jmol Viewer 4MT4	Su et al. (2014). Su CC, Radhakrishnan A, Kumar N, Long F, Bolla JR, Lei HT, Delmar JA, Do SV, Chou TH, Rajashankar KR, Zhang Q, & Yu EW (2014). Crystal structure of the Campylobacter jejuni CmeC outer membrane channel. Protein Sci 23 7:954-961. PubMed Id: 24753291. doi:10.1002/pro.2478.
*VceC outer membrane protein: Vibrio cholerae* B Bacteria, 1.8 Å** NOTE: Functional protein is a homotrimer. Each monomer contributes 4 strands to a single barrel.	1YC9	Data File Jmol Viewer 1YC9	Federici et al. (2005). Federici L, Du D, Walas F, Matsumura H, Fernandez-Recio J, McKeegan KS, Borges-Walmsley MI, Luisi BF, & Walmsley AR (2005). The Crystal Structure of the Outer Membrane Protein VceC from the Bacterial Pathogen Vibrio cholerae at 1.8 A Resolution. J Biol Chem 280 :15307-15314. PubMed Id: 15684414.
*OprM drug discharge outer membrane protein: Pseudomonas aeruginosa* B Bacteria, 2.56 Å** Functional protein is a homotrimer. Each monomer contributes 4 strands to a single barrel. H32 space group. OprM is the discharge channel for the tripartite efflux complex MexAB-OprM. The structures of MexB (the inner membrane efflux pump) and MexA (periplasmic fusion protein) are known. See 2V50 and 1T5E, respectively. See 6IOK for structure of entire complex.	1WP1	Data File Jmol Viewer 1WP1	Akama et al. (2004). Akama H, Kanemaki M, Yoshimura M, Tsukihara T, Kashiwagi T, Yoneyama H, Narita S, Nakagawa A, & Nakae T (2004). Crystal structure of the drug discharge outer membrane protein, OprM, of Pseudomonas aeruginosa: dual modes of membrane anchoring and occluded cavity end. J Biol Chem 279 :52816-52819. PubMed Id: 15507433.
*OprM drug discharge outer membrane protein: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.40 Å** Structure of OprM in a non-symmetrical space group, P2₁2₁2₁	3D5K	Data File Jmol Viewer 3D5K	Phan et al. (2010). Phan G, Benabdelhak H, Lascombe MB, Benas P, Rety S, Picard M, Ducruix A, Etchebest C, & Broutin I (2010). Structural and dynamical insights into the opening mechanism of P. aeruginosa OprM channel. Structure 18 :507-517. PubMed Id: 20399187.
*OprN drug discharge outer membrane protein, I4 space group: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 1.69 Å** P321 space group, 2.70 Å: 5AZP	5AZO	Data File Jmol Viewer 5AZO 5AZP	Yonehara et al. (2016). Yonehara R, Yamashita E, & Nakagawa A (2016). Crystal structures of OprN and OprJ, outer membrane factors of multidrug tripartite efflux pumps of Pseudomonas aeruginosa. Proteins 84 6:759-769. PubMed Id: 26914226. doi:10.1002/prot.25022.
*OprJ drug discharge outer membrane protein: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 3.10 Å**	5AZS	Data File Jmol Viewer 5AZS	Yonehara et al. (2016). Yonehara R, Yamashita E, & Nakagawa A (2016). Crystal structures of OprN and OprJ, outer membrane factors of multidrug tripartite efflux pumps of Pseudomonas aeruginosa. Proteins 84 6:759-769. PubMed Id: 26914226. doi:10.1002/prot.25022.
*ST50 discharge outer membrane protein: Salmonella enterica* B Bacteria (expressed in E. coli), 2.98 Å** Functional protein is a homotrimer. Each monomer contributes 4 strands to a single barrel.	5BUN	Data File Jmol Viewer 5BUN	Guan et al. (2015). Guan HH, Yoshimura M, Chuankhayan P, Lin CC, Chen NC, Yang MC, Ismail A, Fun HK, & Chen CJ (2015). Crystal structure of an antigenic outer-membrane protein from Salmonella Typhi suggests a potential antigenic loop and an efflux mechanism. Sci Rep 5 :16441. PubMed Id: 26563565. doi:10.1038/srep16441.
*CusC heavy metal discharge outer membrane protein: Escherichia coli* B Bacteria, 2.30 Å** NOTE: Functional protein is a homotrimer. Each monomer contributes 4 strands to a single barrel. H32 space group.	3PIK	Data File Jmol Viewer 3PIK	Kulathila et al. (2011). Kulathila R, Kulathila R, Indic M, & van den Berg B (2011). Crystal structure of Escherichia coli CusC, the outer membrane component of a heavy metal efflux pump. PLoS One 6 :e15610. PubMed Id: 21249122. doi:10.1371/journal.pone.0015610.
*CusC heavy metal discharge outer membrane protein: Escherichia coli* B Bacteria, 2.09 Å** ΔC1 mutant, 2.53 Å: 4K7K C1S mutant, 2.69 Å: 4K34	4K7R	Data File Jmol Viewer 4K7R 4K7K 4K34	Lei et al. (2014). Lei HT, Bolla JR, Bishop NR, Su CC, & Yu EW (2014). Crystal Structures of CusC Review Conformational Changes Accompanying Folding and Transmembrane Channel Formation. J Mol Biol 426 :403-411. PubMed Id: 24099674. doi:10.1016/j.jmb.2013.09.042.
*apo BtuB cobalamin transporter: Escherichia coli* B Bacteria, 2.0 Å** Related structures: 1NQF (SeMet-BtuB), 1NQG (Ca²⁺-BtuB), 1NQH (Ca²⁺-B₁₂-BtuB).	1NQE	Data File Jmol Viewer 1NQE 1NQH 1NQF 1NQG vitamin B12 receptor	Chimento et al. (2003). Chimento DP, Mohanty AK, Kadner RJ, & Wiener MC (2003). Substrate-induced transmembrane signaling in the cobalamin transporter BtuB. Nat Struct Biol. 10 :394-401. PubMed Id: 12652322.
*BtuB with bound colicin E3 R-domain: Escherichia coli* B Bacteria, 2.75 Å** NOTE: The 135-residue coiled-coil R-domain is believed to deliver the colicin to OmpF (above).	1UJW	Data File Jmol Viewer 1UJW	Kurisu et al. (2003). Kurisu G, Zakharov SD, Zhalnina MV, Bano S, Eroukova VY, Rokitskaya TI, Antonenko YN, Wiener MC, & Cramer WA (2003). The structure of BtuB with bound colicin E3 R-domain implies a translocon. Nat. Struct. Biol. 10 :948-954. PubMed Id: 14528295.
*apo BtuB by in meso* crystallization: Escherichia coli B Bacteria, 1.95 Å** NOTE: Crystals were prepared from cubic phase lipids. This is the first β-barrel protein prepared by this method.	2GUF	Data File Jmol Viewer 2GUF	Cherezov et al. (2006). Cherezov V, Yamashita E, Liu W, Zhalnina M, Cramer WA & Caffrey M (2006). In meso structure of the cobalamin transporter, BtuB, at 1.95 Å resolution. J Mol Biol 364 :716-734. PubMed Id: 17028020.
*BtuB in complex with TonB: Escherichia coli* B Bacteria, 2.1 Å**	2GSK	Data File Jmol Viewer 2GSK	Shultis et al. (2006). Shultis DD, Purdy MD, Banchs CN, & Wiener MC (2006). Outer membrane active transport: structure of the BtuB:TonB complex. Science 312 :1396-1399. PubMed Id: 16741124.
*BtuB with bound colicin E2 R-domain: Escherichia coli* B Bacteria, 3.50 Å**	2YSU	Data File Jmol Viewer 2YSU	Sharma et al. (2007). Sharma O, Yamashita E, Zhalnina MV, Zakharov SD, Datsenko KA, Wanner BL, & Cramer WA (2007). Structure of the complex of the colicin E2 R-domain and its BtuB receptor. The outer membrane colicin translocon. J Biol Chem 282 :23163-23170. PubMed Id: 17548346.
*apo BtuB V10R1 spin-labeled: Escherichia coli* B Bacteria, 2.44 Å** Spin-labeled BtuB V10R1 with bound calcium and cyanocobalamin, 2.44 Å: 3M8D	3M8B	Data File Jmol Viewer 3M8B 3M8D	Freed et al. (2010). Freed DM, Horanyi PS, Wiener MC, & Cafiso DS (2010). Conformational exchange in a membrane transport protein is altered in protein crystals. Biophys J 99 :1604-1610. PubMed Id: 20816073. doi:10.1016/j.bpj.2010.06.026.
*Colicin I receptor Cir in complex with Colicin Ia binding domain: Escherichia coli* B Bacteria, 2.5 Å** Cir Colicin I receptor alone, 2.65 Å: 2HDF	2HDI	Data File Jmol Viewer 2HDI 2HDF	Buchanan et al. (2007). Buchanan S, Lukacik P, Grizot S, Ghirlando R, Ali MMU, Barnard TJ, Jakes S, Kienker PK, & Esser L. (2007). Structure of colicin I receptor bound to the R-domain of colicin Ia: Implications for protein import. EMBO J 26 :2594-2604. PubMed Id: 17464289.
*OmpA: Escherichia coli* B Bacteria, 2.50 Å**	1BXW	Data File Jmol Viewer 1BXW OmpA	Pautsch & Schulz (1998). Pautsch A & Schulz GE (1998). Structure of the outer membrane protein A transmembrane domain. Nature Struct Biol 5 :1013-1017. PubMed Id: 9808047.
*OmpA: Escherichia coli* B Bacteria, 1.60 Å**	1QJP	Data File Jmol Viewer 1QJP OmpA	Pautsch & Schulz (2000). Pautsch A & Schulz GE (2000). High-resolution structure of the OmpA membrane domain. J Mol Biol 298 :273-282. PubMed Id: 10764596.
*OmpA: Escherichia coli* B Bacteria, NMR Structure** in DPC micelles	1G90	Data File Jmol Viewer 1G90 OmpA	Arora et al. (2001). Arora A, Abildgaard F, Bushweller JH, & Tamm LK (2001). Structure of outer membrane protein A transmembrane domain by NMR spectroscopy. Nature Structural Biol. 8 :334-338. PubMed Id: 11276254.
*OmpA: Escherichia coli* B Bacteria, NMR structure** DPC micelles. High-resolution structure determined using residual dipolar couplings.	2GE4	Data File Jmol Viewer 2GE4	Cierpicki et al. (2006). Cierpicki T, Liang B, Tamm LK, & Bushweller JH (2006). Increasing the accuracy of solution NMR structures of membrane proteins by application of residual dipolar couplings. High-resolution structure of outer membrane protein A. J Am Chem Soc 128 :6947-6951. PubMed Id: 16719475.
*OmpA with four shortened loops: Escherichia coli* B Bacteria, NMR Structure** DHPC micelles. Called β-barrel platform (BBP).	2JMM	Data File Jmol Viewer 2JMM	Johansson et al. (2007). Johansson MU, Alioth S, Hu K, Walser R, Koebnik R, & Pervushin K (2007). A minimal transmembrane β-barrel platform protein studied by nuclear magnetic resonance. Biochemistry 46 :1128-1140. PubMed Id: 17260943.
*OmpA: Klebsiella pneumoniae* B Bacteria (expressed in E. coli), NMR Structure** DHPC micelles	2K0L	Data File Jmol Viewer 2K0L	Renault et al. (2009). Renault M, Saurel O, Czaplicki J, Demange P, Gervais V, Löhr F, Réat V, Piotto M, & Milon A (2009). Solution state NMR structure and dynamics of KpOmpA, a 210 residue transmembrane domain possessing a high potential for immunological applications J Mol Biol 385 :117-130. PubMed Id: 18952100. doi:10.1016/j.jmb.2008.10.021.
*OmpT outer membrane protease: Escherichia coli* B Bacteria, 2.6 Å**	1I78	Data File Jmol Viewer 1I78 OmpT	Vandeputte-Rutten et al. (2001). Vandeputte-Rutten L, Kramer RA, Kroon J, Dekker N, Egmond, MR, & Gros P (2001). Crystal structure of the outer membrane protease OmpT from Eschericia coli suggests a novel catalytic site. EMBO J 20 :5033-5039. PubMed Id: 11566868.
*Pla Plasminogen activator (native 1): Yersinia pestis* B Bacteria (expressed in E. coli), 1.90 Å** Wild-type (Native 2), 2.30 Å: 2X56 D86A mutant, 2.55 Å: 2X4M	2X55	Data File Jmol Viewer 2X55 2X4M 2X56	Eren et al. (2010). Eren E, Murphy M, Goguen J, & van den Berg B. (2010). An active site water network in the plasminogen activator Pla from Yersinia pestis. Structure 18 :809-818. PubMed Id: 20637417.
*OmpW outer membrane protein: Escherichia coli* B Bacteria, 2.7 Å** 2F1V is orthorhomibic form. Trigonal form, 3.0 Å: 2F1T	2F1V	Data File Jmol Viewer 2F1V 2F1T OmpW	Hong et al. (2006). Hong H, Patel DR, Tamm LK, & van den Berg B (2006). The Outer Membrane Protein OmpW Forms an Eight-stranded beta-Barrel with a Hydrophobic Channel. J Biol Chem 281 :7568-7577. PubMed Id: 16414958.
*OmpW outer membrane protein: Escherichia coli* B Bacteria, NMR structure** 30-Fos detergent	2MHL	Data File Jmol Viewer 2MHL	Horst et al. (2014). Horst R, Stanczak P, & Wüthrich K (2014). NMR polypeptide backbone conformation of the E. coli outer membrane protein W. Structure 22 :1204-1209. PubMed Id: 25017731. doi:10.1016/j.str.2014.05.016.
*AlkL passive importer of hydrophobic molecules in DMPC lipid bilayer: Pseudomonas oleovorans* B Bacteria (expressed in E. coli), NMR structure** Solution NMR structure, 6QAM	6QWR	Data File Jmol Viewer 6QWR 6QAM	Schubeis et al. (2020). Schubeis T, Le Marchand T, Daday C, Kopec W, Tekwani Movellan K, Stanek J, Schwarzer TS, Castiglione K, de Groot BL, Pintacuda G, & Andreas LB (2020). A β-barrel for oil transport through lipid membranes: Dynamic NMR structures of AlkL. Proc Natl Acad Sci USA 117 35:21014-21021. PubMed Id: 32817429. doi:10.1073/pnas.2002598117.
*CarO outer membrane protein, isoform 1: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 2.70 Å** isoform 2, 2.70 Å: 4RLB isoform 3, 2.15 Å: 4FUV	4RL9	Data File Jmol Viewer 4RL9 4FUV 4RLB	Zahn et al. (2015). Zahn M, D'Agostino T, Eren E, Baslé A, Ceccarelli M, & van den Berg B (2015). Small-Molecule Transport by CarO, an Abundant Eight-Stranded β-Barrel Outer Membrane Protein from Acinetobacter baumannii. J Mol Biol 427 :2329-2339. PubMed Id: 25846137. doi:10.1016/j.jmb.2015.03.016.
*OprF outer membrane protein, N-terminal β-barrel domain: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 1.6 Å**	4RLC	Data File Jmol Viewer 4RLC	Zahn et al. (2015). Zahn M, D'Agostino T, Eren E, Baslé A, Ceccarelli M, & van den Berg B (2015). Small-Molecule Transport by CarO, an Abundant Eight-Stranded β-Barrel Outer Membrane Protein from Acinetobacter baumannii. J Mol Biol 427 :2329-2339. PubMed Id: 25846137. doi:10.1016/j.jmb.2015.03.016.
*OprG outer membrane protein: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.4 Å** Potential channel for hydrophobic molecule transport	2X27	Data File Jmol Viewer 2X27	Touw et al. (2010). Touw DS, Patel DR, & van den Berg B (2010). The crystal structure of OprG from Pseudomonas aeruginosa, a potential channel for transport of hydrophobic molecules across the outer membrane. PLoS One 5 :e15016. PubMed Id: 21124774. doi:10.1371/journal.pone.0015016.
*OprH, outer membrane protein H: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), NMR Structure** Structure determined in DHPC micelles. Eight strands. Chemical-shift measurements identify likely lipopolysaccharide interaction sites.	2LHF	Data File Jmol Viewer 2LHF	Edrington et al. (2011). Edrington TC, Kintz E, Goldberg JB, & Tamm LK (2011). Structural Basis for the Interaction of Lipopolysaccharide with Outer Membrane Protein H (OprH) from Pseudomonas aeruginosa J Biol Chem 286 :39211-39223. PubMed Id: 21865172. doi:10.1074/jbc.M111.280933.
*OmpX: Escherichia coli* B Bacteria, 1.9 Å** Structure at 2.1 Å, 1QJ9	1QJ8	Data File Jmol Viewer 1QJ8 1QJ9 OmpX	Vogt & Schulz (1999). Vogt J & Schulz GE (1999). The structure of the outer membrane protein OmpX from Escherichia coli reveals possible mechanisms of virulence. Structure Fold.Des. 7 :1301-1309. PubMed Id: 10545325.
*OmpX: Escherichia coli* B Bacteria, NMR (DHPC micelles)**	1ORM	Data File Jmol Viewer 1ORM	Fernández et al. (2001). Fernández C, Adeishvili K, & Wüthrich K (2001). Transverse relaxation-optimized NMR spectroscopy with the outer membrane protein OmpX in dihexanoyl phosphatidylcholine micelles. Proc Natl Acad Sci USA 98 :2358-2363. PubMed Id: 11226244.
*OmpX: Escherichia coli* B Bacteria, NMR (DPC micelles, with H-bond constraints)** For structure without H-bond constraints, see 1Q9G	1Q9F	Data File Jmol Viewer 1Q9F 1Q9G	Fernández et al. (2004). Fernández C, Hilty C, Wider G, Guntert P, & Wüthrich K (2004). NMR structure of the integral membrane protein OmpX. J Mol Biol. 336 :1211-1221. PubMed Id: 15037080.
*OmpX in optimized nanodiscs: Escherichia coli* B Bacteria, NMR Structure** In DPC micelles, NMR Structure: 2M07	2M06	Data File Jmol Viewer 2M06 2M07	Hagn et al. (2013). Hagn F, Etzkorn M, Raschle T, & Wagner G (2013). Optimized phospholipid bilayer nanodiscs facilitate high-resolution structure determination of membrane proteins. J Am Chem Soc 135 :1919-1925. PubMed Id: 23294159. doi:10.1021/ja310901f.
*Ail adhesion protein: Yersinia pestis* B Bacteria (expressed in E. coli), 1.80 Å** In complex with sucrose octasulfate (SOS), 1.85 Å: 3QRC	3QRA	Data File Jmol Viewer 3QRA 3QRC	Yamashita et al. (2011). Yamashita S, Lukacik P, Barnard TJ, Noinaj N, Felek S, Tsang TM, Krukonis ES, Hinnebusch BJ, & Buchanan SK (2011). Structural Insights into Ail-Mediated Adhesion in Yersinia pestis. Structure 19 :1672-1682. PubMed Id: 22078566. doi:10.1016/j.str.2011.08.010.
*Ail adhesion protein, decylphosphocholine micelles: Yersinia pestis* B Bacteria (expressed in E. coli), NMR structure** in decylphosphocholine micelles calculated with implicit membrane solvation, NMR structure: 2N2L	2N2M	Data File Jmol Viewer 2N2M 2N2L	Marassi et al. (2015). Marassi FM, Ding Y, Schwieters CD, Tian Y, & Yao Y (2015). Backbone structure of Yersinia pestis Ail determined in micelles by NMR-restrained simulated annealing with implicit membrane solvation. J Biomol NMR 63 :59-65. PubMed Id: 26143069. doi:10.1007/s10858-015-9963-2.
*Ail adhesion protein: Yersinia pestis* B Bacteria (expressed in E. coli), NMR structure** Structure of protein in phospholipid nano-disc. Examines the effect of KDO2-lipid A.	5VJ8	Data File Jmol Viewer 5VJ8	Dutta et al. (2017). Dutta SK, Yao Y, & Marassi FM (2017). Structural Insights into the Yersinia pestis Outer Membrane Protein Ail in Lipid Bilayers. J Phys Chem B 121 :7561-7570. PubMed Id: 28726410. doi:10.1021/acs.jpcb.7b03941.
*TtoA Outer Membrane Protein (OMP): Thermus thermophilus HB27* B Bacteria, 2.8 Å** First structure of an OMP from a thermophile	3DZM	Data File Jmol Viewer 3DZM	Brosig et al. (2009). Brosig A, Nesper J, Boos W, Welte W, & Diederichs K (2009). Crystal structure of a major outer membrane protein from Thermus thermophilus HB27. J Mol Biol 385 :1445-1455. PubMed Id: 19101566.
*OmpLA (PldA) outer membrane phospholipase A monomer: Escherichia coli* B Bacteria, 2.17 Å** Dimer, 2.10 Å: 1QD6	1QD5	Data File Jmol Viewer 1QD5 1QD6 outer membrane phospholipase A	Snijder et al. (1999). Snijder HJ, Ubarretxena-Belandia I, Blaauw M, Kalk KH, Verheij HM, Egmond MR, Dekker N, & Dijkstra BW (1999). Structural evidence for dimerization-regulated activation of an integral membrane phospholipase. Nature 401 :717-721. PubMed Id: 10537112.
*OmpLA (PldA) outer membrane phospholipase A monomer with Ca⁺⁺: Escherichia coli* B Bacteria, 2.60 Å** Dimer, 2.80 Å: 1FW3	1FW2	Data File Jmol Viewer 1FW2 1FW3	Snijder et al. (2001). Snijder HJ, Kingma RL, Kalk KH, Dekker N, Egmond MR, & Dijkstra BW (2001). Structural investigations of calcium binding and its role in activity and activation of outer membrane phospholipase A from Escherichia coli. J Mol Biol 309 :477-489. PubMed Id: 11371166.
*OmpLA (PldA) active-site mutant (N156A), pH 6.1: Escherichia coli* B Bacteria, 2.50 Å** pH 4.6, 2.80 Å: 1ILD pH 8.3, 2.98 Å: 1IM0	1ILZ	Data File Jmol Viewer 1ILZ 1ILD 1IM0	Snijder et al. (2001). Snijder HJ, Van Eerde JH, Kingma RL, Kalk KH, Dekker N, Egmond MR, & Dijkstra BW (2001). Structural investigations of the active-site mutant Asn156Ala of outer membrane phospholipase A: function of the Asn-His interaction in the catalytic triad. Protein Sci 10 :1962-1969. PubMed Id: 11567087.
*OpcA adhesin protein: Neisseria meningitidis* B Bacteria, 2.0 Å**	1K24	Data File Jmol Viewer 1K24 OpcA	Prince et al. (2002). Prince SM, Achtman M, & Derrick JP (2002). Crystal structure of the OpcA integral membrane adhesin from Neisseria meningitidis. Proc. Natl. Acad. Sci. USA 99 :3417-3421. PubMed Id: 11891340.
*OpcA adhesin protein: Neisseria meningitidis* B Bacteria (expressed in E. coli), 1.95 Å** In meso crystallization	2VDF	Data File Jmol Viewer 2VDF	Cherezov et al. (2008). Cherezov V, Liu W, Derrick JP, Luan B, Aksimentiev A, Katritch V, & Caffrey M (2008). In meso crystal structure and docking simulations suggest an alternative proteoglycan binding site in the OpcA outer membrane adhesin. Proteins 71 :24-34. PubMed Id: 18076035. doi:10.1002/prot.21841.
*NspA surface protein: Neisseria meningitidis* B Bacteria, 2.55 Å**	1P4T	Data File Jmol Viewer 1P4T NspA surface protein A	Vandeputte-Rutten et al. (2003). Vandeputte-Rutten L, Bos MP, Tommassen J, & Gros P (2003). Crystal structure of Neisserial surface protein A (NspA), a conserved outer membrane protein with vaccine potential. J. Biol. Chem. 278 :24825-24830. PubMed Id: 12716881.
*NanC Porin, model for KdgM porin family: Escherichia coli* B Bacteria, 1.80 Å** H3 space group. See also 2WJQ, p6₃22 space group, 2.0 Å resolution.	2WJR	Data File Jmol Viewer 2WJR 2WJQ	Wirth et al. (2009). Wirth C, Condemine G, Boiteux C, Bernèche S, Schirmer T, & Peneff CM (2009). NanC Crystal Structure, a Model for Outer-Membrane Channels of the Acidic Sugar-Specific KdgM Porin Family. J Mol Biol 394 :718-731. PubMed Id: 19796645.
*PagL LPS 3-O-deacylase: Pseudomonas aeruginosa* B Bacteria, 2.00 Å**	2ERV	Data File Jmol Viewer 2ERV	Rutten et al. (2006). Rutten L, Geurtsen J, Lambert W, Smolenaers JJ, Bonvin AM, de Haan A, van der Ley P, Egmond MR, Gros P, & Tommassen J (2006). Crystal structure and catalytic mechanism of the LPS 3-O-deacylase PagL from Pseudomonas aeruginosa. Proc Natl Acad Sci USA 103 :7071-7076. PubMed Id: 16632613. doi:10.1073/pnas.0509392103.
*LpxR lipid A deacylase: Salmonella typhimurium* B Bacteria (expressed in E. coli), 1.90 Å**	3FID	Data File Jmol Viewer 3FID	Rutten et al. (2009). Rutten L, Mannie JP, Stead CM, Raetz CR, Reynolds CM, Bonvin AM, Tommassen JP, Egmond MR, Trent MS, & Gros P (2009). Active-site architecture and catalytic mechanism of the lipid A deacylase LpxR of Salmonella typhimurium. Proc Natl Acad Sci USA 106 :1960-1964. PubMed Id: 19174515. doi:10.1073/pnas.0813064106 .
*PagP outer membrane palimitoyl transferease: Escherichia coli* B Bacteria, NMR** 1MM4 is Structure in DPC micelles. Structure in OG micelles: 1MM5	1MM4	Data File Jmol Viewer 1MM4 1MM5 PagP	Hwang et al. (2002). Hwang PM, Choy WY, Lo EI, Chen L, Forman-Kay JD, Raetz CR, Privé GG, Bishop RE, Kay LE (2002). Solution structure and dynamics of the outer membrane enzyme PagP by NMR. Proc Natl Acad Sci USA 99 :13560-13565. PubMed Id: 12357033.
*PagP outer membrane palimitoyl transferease: Escherichia coli* B Bacteria, 1.90 Å**	1THQ	Data File Jmol Viewer 1THQ	Ahn et al. (2004). Ahn VE, Lo EI, Engel CK, Chen L, Hwang PM, Kay LE, Bishop RE, & Prive GG (2004). A hydrocarbon ruler measures palmitate in the enzymatic acylation of endotoxin. EMBO J. 23 :2931-2941. PubMed Id: 15272304.
*PagP outer membrane palimitoyl transferease crystallized from SDS/Co-solvent: Escherichia coli* B Bacteria, 1.40 Å** Reveals phospholipid access route (crenel between strands F and G)	3GP6	Data File Jmol Viewer 3GP6	Cuesta-Seijo et al. (2010). Cuesta-Seijo JA, Neale C, Khan MA, Moktar J, Tran CD, Bishop RE, Pomès R, & Privé GG (2010). PagP crystallized from SDS/cosolvent reveals the route for phospholipid access to the hydrocarbon ruler. Structure 18 :1210-1219. PubMed Id: 20826347.
*FadL long-chain fatty acid transporter: Escherichia coli* B Bacteria, 2.6 Å** 1T16 is from Monoclinic crystals. From hexagonal crystals, 2.8 Å: 1T1L	1T16	Data File Jmol Viewer 1T16 1T1L FadL	van den Berg et al. (2004). van den Berg B, Black PN, Clemons WM Jr, & Rapoport TA (2004). Crystal structure of the long-chain fatty acid transporter FadL. Science 304 :1506-1509. PubMed Id: 15178802.
*FadL long-chain fatty acid transporter A77E/S100R mutant: Escherichia coli* B Bacteria, 2.5 Å** Mutants show that channel wall opening for passage of fatty acids into inner layer of outer membrane is likely. ΔS3 kink, 2.60 Å: 2R88 P34A mutant, 3.3 Å: 2R4L N33A mutant, 3.2 Å: 2R4N ΔNPA mutant, 3.6 Å: 2R4O G212E mutant, 2.9 Å: 2R4P	3DWN	Data File Jmol Viewer 3DWN 2R4O 2R4N 2R4P 2R4L 2R88	Hearn et al. (2009). Hearn EM, Patel DR, Lepore BW, Indic M, van den Berg B (2009). Transmembrane passage of hydrophobic compounds through a protein channel wall. Nature 458 :367-370. PubMed Id: 19182779.
*FadL long-chain fatty acid transporter D348R mutant: Escherichia coli* B Bacteria, 2.60 Å** This and associated structures in conjunction with in vivo transport assays and Trp fluorescence demonstrate ligand gating of the β-barrel protein. delta N3 mutant, 3.40 Å: 2R89 D348A mutant, 2.70 Å: 3PF1 F3E mutant, 1.70 Å: 3PGU F3G mutant, 1.90 Å: 3PGS	3PGR	Data File Jmol Viewer 3PGR 2R89 3PGS 3PF1 3PGU	Lepore et al. (2011). Lepore BW, Indic M, Pham H, Hearn EM, Patel DR, & van den Berg B (2011). Ligand-gated diffusion across the bacterial outer membrane Proc Natl Acad Sci USA 108 :10121-10126. PubMed Id: 21593406. doi:10.1073/pnas.1018532108.
*FadL homologue long-chain fatty acid transporter: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.2 Å** Shows break in channel wall for passage of fatty acids into inner layer of outer membrane in a species other than E. coli. Residues 22-463.	3DWO	Data File Jmol Viewer 3DWO	Hearn et al. (2009). Hearn EM, Patel DR, Lepore BW, Indic M, van den Berg B (2009). Transmembrane passage of hydrophobic compounds through a protein channel wall. Nature 458 :367-370. PubMed Id: 19182779.
*YebT lipid transporter, domains 1-4: Escherichia coli* B Bacteria, 3.1 Å** cryo-EM structure domains 5-7, 3 Å: 6KZ4	6KZ3	Data File Jmol Viewer 6KZ3 6KZ4	Liu et al. (2020). Liu C, Ma J, Wang J, Wang H, & Zhang L (2020). Cryo-EM Structure of a Bacterial Lipid Transporter YebT. J Mol Biol 432 4:1008-1019. PubMed Id: 31870848. doi:10.1016/j.jmb.2019.12.008.
*FauA alcaligin outer membrane transporter: Bordetella pertussis* B Bacteria (expressed in E. coli), 2.3 Å**	3EFM	Data File Jmol Viewer 3EFM	Brillet et al. (2009). Brillet K, Meksem A, Lauber E, Reimmann & C, Cobessi D (2009). Use of an in-house approach to study the three-dimensional structures of various outer membrane proteins: structure of the alcaligin outer membrane transporter FauA from Bordetella pertussis. Acta Crystallogr D Biol Crystallogr 65 :326-331. PubMed Id: 19307713.
*TodX hydrocarbon transporter: Pseudomonas putida* B Bacteria, 2.6 Å** 3BS0 is P1 space group, 2 molecules in asymmetric unit. I222 space group, 3.2 Å: 3BRZ	3BS0	Data File Jmol Viewer 3BS0 3BRZ	Hearn et al. (2008). Hearn EM, Patel DR, & van den Berg BO (2008). Outer-membrane transport of aromatic hydrocarbons as a first step in biodegradation. Proc Natl Acad Sci USA 105 :8601-8606. PubMed Id: 18559855.
*TbuX hydrocarbon transporter: Ralstonia pickettii* B Bacteria, 3.2 Å**	3BRY	Data File Jmol Viewer 3BRY	Hearn et al. (2008). Hearn EM, Patel DR, & van den Berg BO (2008). Outer-membrane transport of aromatic hydrocarbons as a first step in biodegradation. Proc Natl Acad Sci USA 105 :8601-8606. PubMed Id: 18559855.
*Tsx nucleoside transporter (apoprotein): Escherichia coli* B Bacteria, 3.0 Å** Protein + thymidine, 3.10 Å: 1TLW Protein + uridine, 3.10 Å: 1TLZ	1TLY	Data File Jmol Viewer 1TLY 1TLZ 1TLW	Ye and van den Berg (2004). Ye J & van den Berg B (2004). Crystal structure of the bacterial nucleoside transporter Tsx. EMBO J. 23 :3187-3195. PubMed Id: 15272310.
*FhuA, Ferrichrome-iron receptor without ligand: Escherichia coli* B Bacteria, 2.7 Å** With ligand: 1BY5	1BY3	Data File Jmol Viewer 1BY3 1BY5	Locher et al. (1998). Locher KP, Rees B, Koebnik R, Mitschler A, Moulinier L, Rosenbusch JP, & Moras D (1998). Transmembrane signaling across the ligand-gated FhuA receptor: crystal structures of free and ferrichrome-bound states reveal allosteric changes. Cell 11 :771-8. PubMed Id: 9865695.
*FhuA: Escherichia coli* B Bacteria, 2.50 Å** Includes the structure of a bound lipopolysaccharide (LPS) molecule In complex with ferrichrome-iron, 2.70 Å: 1FCP	2FCP	Data File Jmol Viewer 2FCP 1FCP Ferric hydroxamate uptake receptor	Ferguson et al. (1998). Ferguson AD, Hofmann E, Coulton JW, Diederichs K, & Welte W (1998). Siderophore-mediated iron transport: crystal structure of FhuA with bound lipopolysaccharide. Protein Sci 9 :956-963. PubMed Id: 9856937.
*FhuA-AW140-LPS: Escherichia coli* B Bacteria, 2.5 Å** Structure of lipopolysaccharide (LPS) in complex with FhuA. FhuA-DL41-LPS-ferricrocin, 2.7 Å: 1QFF	1QFG	Data File Jmol Viewer 1QFG 1QFF	Ferguson et al. (2000). Ferguson AD, Welte W, Hofmann E, Lindner B, Holst O, Coulton JW, & Diederichs K (2000). A conserved structural motif for lipopolysaccharide recognition by procaryotic and eucaryotic proteins. Structure 8 :585-592. PubMed Id: 10873859.
*FhuA in complex with albomycin: Escherichia coli* B Bacteria, 3.10 Å** In complex with phenylferricrocin, 2.95 Å: 1QJQ	1QKC	Data File Jmol Viewer 1QKC 1QJQ	Ferguson et al. (2000). Ferguson AD, Braun V, Fiedler HP, Coulton JW, Diederichs K, & Welte W (2000). Crystal structure of the antibiotic albomycin in complex with the outer membrane transporter FhuA. Science 282 :2215-2220. PubMed Id: 10850805.
*FhuA in complex with lipopolysaccharide and rifamycin CGP4832: Escherichia coli* B Bacteria, 2.90 Å**	1FI1	Data File Jmol Viewer 1FI1	Ferguson et al. (2001). Ferguson AD, Ködding J, Walker G, Bös C, Coulton JW, Diederichs K, Braun V, & Welte W (2001). Active transport of an antibiotic rifamycin derivative by the outer-membrane protein FhuA. Structure 9 :707-716. PubMed Id: 11587645.
*FhuA in complex withTonB: Escherichia coli* B Bacteria, 3.3 Å**	2GRX	Data File Jmol Viewer 2GRX	Pawelek et al. (2006). Pawelek PD, Croteau N, Ng-Thow-Hing C, Khursigara CM, Moiseeva N, Allaire M, & Coulton JW (2006). Structure of TonB in complex with FhuA, E. coli outer membrane receptor. Science 312 :1399-1402. PubMed Id: 16741125.
*FhuA in complex with lasso peptide microcin J25 (MccJ25): Escherichia coli* B Bacteria, 2.30 Å**	4CU4	Data File Jmol Viewer 4CU4	Mathavan et al. (2014). Mathavan I, Zirah S, Mehmood S, Choudhury HG, Goulard C, Li Y, Robinson CV, Rebuffat S, & Beis K (2014). Structural basis for hijacking siderophore receptors by antimicrobial lasso peptides. Nat Chem Biol 10 5:340-342. PubMed Id: 24705590. doi:10.1038/nchembio.1499.
*FhuA in complex with superinfection exclusion (SE) lipoprotein Llp: Escherichia coli* B Bacteria, 3.37 Å** In complex with T5 phage receptor-binding protein (RBP) pb5, cryo-EM structure, 3.1 Å: 8A8C	8A60	Data File Jmol Viewer 8A60 8A8C	van den Berg et al. (2022). van den Berg B, Silale A, Baslé A, Brandner AF, Mader SL, & Khalid S (2022). Structural basis for host recognition and superinfection exclusion by bacteriophage T5. Proc Natl Acad Sci U S A 119 42:e2211672119. PubMed Id: 36215462. doi:10.1073/pnas.2211672119.
*FyuA siderophore transporter: Yersinia pestis* B Bacteria (expressed in E. coli), 3.20 Å** pesticin bacteriocin toxin, 2.09 Å: 4EPF phage lysin containing the binding domain of pesticin and the killing domain of T4-lysozyme, 2.60 Å: 4EXM pesticin-T4 lysozyme hybrid stabilized by engineered disulfide bonds, 1.74 Å: 4EPI	4EPA	Data File Jmol Viewer 4EPA 4EXM 4EPI 4EPF	Lukacik et al. (2012). Lukacik P, Barnard TJ, Keller PW, Chaturvedi KS, Seddiki N, Fairman JW, Noinaj N, Kirby TL, Henderson JP, Steven AC, Hinnebusch BJ, & Buchanan SK (2012). Structural engineering of a phage lysin that targets gram-negative pathogens. Proc Natl Acad Sci USA 109 25:9857-9862. PubMed Id: 22679291. doi:10.1073/pnas.1203472109.
*FepA, Ferric enterobactin receptor: Escherichia coli* B Bacteria, 2.4 Å**	1FEP	Data File Jmol Viewer 1FEP FepA	Buchanan et al. (1999). Buchanan S, Smith BS, Venkatramani L, Xia D, Esser L, Palnitkar M, Chakraborty R, van der Helm D, & Deisenhofer J. (1999). Crystal Structure of the outer membrane active transporter FepA from Escherichia coli. Nature Structural Biol 6 :56-63. PubMed Id: 9886293.
*Fiu Ferric-Catecholate import receptor, open C222(1) crystal form: B Bacteria (expressed in Escherichia coli), 2.1 Å* Closed form (C21), 2.5 Å: 6BPM Closed form (P1), 2.9 Å: 6BPO	6BPN	Data File Jmol Viewer 6BPN 6BPO 6BPM	Grinter & Lithgow (2019). Grinter R, & Lithgow T (2019). The structure of the bacterial iron-catecholate transporter Fiu suggests that it imports substrates via a two-step mechanism. J Biol Chem 294 51:19523-19534. PubMed Id: 31712312. doi:10.1074/jbc.RA119.011018.
*FecA, siderophore transporter: Escherichia coli* B Bacteria, 2.0 Å** Structure at 2.5 Å: 1KMP	1KMO	Data File Jmol Viewer 1KMO 1KMP FecA	Ferguson et al. (2002). Ferguson AD, Chakraborty R, Smith BS, Esser L, van der Helm D, & Deisenhofer, J (2002). Structural basis of gating by the outer Membrane transporter FecA. Science 295 :1715-1719. PubMed Id: 11872840.
*FecA, siderophore transporter (no ligand): Escherichia coli* B Bacteria, 2.5 Å** FecA with iron-free dicitrate, 2.15 Å: : 1PO0 FecA with diferric dicitrate, 3.4 Å: : 1PO3	1PNZ	Data File Jmol Viewer 1PNZ 1PO3 1PO0	Yue et al. (2003). Yue WW, Grizot S, & Buchanan SK (2003). Structural evidence for iron-free citrate and ferric citrate binding to the TonB-dependent outer membrane transporter FecA. J Mol Biol 332 :353-368. PubMed Id: 12948487.
*FecA, siderophore transporter periplasmic signalling domain: Escherichia coli* B Bacteria, NMR Structure** Shows the signalling domain not seen x-ray structures	2D1U	Data File Jmol Viewer 2D1U	Garcia-Herrero & Vogel (2005). Garcia-Herrero A & Vogel HJ (2005). Nuclear magnetic resonance solution structure of the periplasmic signalling domain of the TonB-dependent outer membrane transporter FecA from Escherichia coli. Mol Microbiol 58 :1226-1237. PubMed Id: 16313612.
*PiuA siderophore receptor: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 1.90 Å**	5FOK	Data File Jmol Viewer 5FOK	Moyniéet al. (2017). Moynié L, Luscher A, Rolo D, Pletzer D, Tortajada A, Weingart H, Braun Y, Page MG, Naismith JH, & Köhler T (2017). Structure and Function of the PiuA and PirA Siderophore-Drug Receptors from Pseudomonas aeruginosa and Acinetobacter baumannii. Antimicrob Agents Chemother 61 4. PubMed Id: 28137795. doi:10.1128/AAC.02531-16.
*PiuD siderophore receptor: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.30 Å**	5NEC	Data File Jmol Viewer 5NEC	Luscher et al. (2018). Luscher A, Moynié L, Auguste PS, Bumann D, Mazza L, Pletzer D, Naismith JH, & Köhler T (2018). TonB-Dependent Receptor Repertoire of Pseudomonas aeruginosa for Uptake of Siderophore-Drug Conjugates. Antimicrob Agents Chemother 62 6. PubMed Id: 29555629. doi:10.1128/AAC.00097-18.
*PiuA siderophore receptor: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 1.94 Å**	5FP1	Data File Jmol Viewer 5FP1	Moyniéet al. (2017). Moynié L, Luscher A, Rolo D, Pletzer D, Tortajada A, Weingart H, Braun Y, Page MG, Naismith JH, & Köhler T (2017). Structure and Function of the PiuA and PirA Siderophore-Drug Receptors from Pseudomonas aeruginosa and Acinetobacter baumannii. Antimicrob Agents Chemother 61 4. PubMed Id: 28137795. doi:10.1128/AAC.02531-16.
*PirA siderophore receptor: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.97 Å**	5FP2	Data File Jmol Viewer 5FP2	Moyniéet al. (2017). Moynié L, Luscher A, Rolo D, Pletzer D, Tortajada A, Weingart H, Braun Y, Page MG, Naismith JH, & Köhler T (2017). Structure and Function of the PiuA and PirA Siderophore-Drug Receptors from Pseudomonas aeruginosa and Acinetobacter baumannii. Antimicrob Agents Chemother 61 4. PubMed Id: 28137795. doi:10.1128/AAC.02531-16.
*PirA siderophore receptor: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 2.83 Å**	5FR8	Data File Jmol Viewer 5FR8	Moyniéet al. (2017). Moynié L, Luscher A, Rolo D, Pletzer D, Tortajada A, Weingart H, Braun Y, Page MG, Naismith JH, & Köhler T (2017). Structure and Function of the PiuA and PirA Siderophore-Drug Receptors from Pseudomonas aeruginosa and Acinetobacter baumannii. Antimicrob Agents Chemother 61 4. PubMed Id: 28137795. doi:10.1128/AAC.02531-16.
*HasR heme-uptake receptor in complex with HasA hemophore and heme: Serratia marcescens* B Bacteria (expressed in E. coli), 2.7 Å** HasA~HasR, 3.0 Å: 3CSN HasA~HasR[I671G]~heme, 2.8 Å: 3DDR	3CSL	Data File Jmol Viewer 3CSL 3CSN 3DDR	Krieg et al. (2009). Krieg S, Huché F, Diederichs K, Izadi-Pruneyre N, Lecroisey A, Wandersman C, Delepelaire P, & Welte W. (2009). Heme uptake across the outer membrane as revealed by crystal structures of the receptor-hemophore complex. Proc Natl Acad Sci USA 106 :1045-1050. PubMed Id: 19144921.
*ShuA heme-uptake receptor in complex with HasA hemophore and heme: Shigella dysenteriae* B Bacteria (expressed in E. coli), 2.6 Å**	3FHH	Data File Jmol Viewer 3FHH	Cobessi et al. (2010). Cobessi D, Meksem A, & Brillet K (2010). Structure of the heme/hemoglobin outer membrane receptor ShuA from Shigella dysenteriae: heme binding by an induced fit mechanism. Proteins 78 :286-294. PubMed Id: 19731368. doi:10.1002/prot.22539.
*FptA pyochelin siderophore transporter: Pseudomonas aeruginosa* B Bacteria, 2.0 Å**	1XKW	Data File Jmol Viewer 1XKW FptA	Cobessi et al. (2005). Cobessi D, Celia H, Pattus F (2005). Crystal structure at high resolution of ferric-pyochelin and its membrane receptor FptA from Pseudomonas aeruginosa. J Mol Biol 352 :893-904. PubMed Id: 16139844.
*FptA pyochelin siderophore transporter: Pseudomonas fluorescens* B Bacteria, 3.26 Å**	3QLB	Data File Jmol Viewer 3QLB	Brillet et al. (2011). Brillet K, Reimmann C, Mislin GL, Noël S, Rognan D, Schalk IJ, & Cobessi D (2011). Pyochelin enantiomers and their outer-membrane siderophore transporters in fluorescent pseudomonads: structural bases for unique enantiospecific recognition. J Am Chem Soc 133 41:16503-16509. PubMed Id: 21902256. doi:10.1021/ja205504z.
*FpvA, Pyoverdine receptor: Pseudomonas aeruginosa* B Bacteria, 3.6 Å**	1XKH	Data File Jmol Viewer 1XKH	Cobessi et al. (2005). Cobessi D, Celia H, Folschweiller N, Schaik IJ, Abdallah MA, & Pattus F (2005). The crystal structure of the pyoverdine outer membrane receptor FpvA from Pseudomonas aeruginosa at 3.6 Å resolution. J Mol Biol 347 :121-134. PubMed Id: 15733922.
*FpvA, Pyoverdine receptor (apo form): Pseudomonas aeruginosa* B Bacteria, 2.77 Å**	2O5P	Data File Jmol Viewer 2O5P	Brillet et al. (2007). Brillet K, Journet L, Célia H, Paulus L, Stahl A, Pattus F, & Cobessi D (2007). A β strand lock exchange for signal transduction in TonB-dependent transducers on the basis of a common structural motif. Structure 15 :1383-1391. PubMed Id: 17997964.
*FpvA, Full-length structure bound to iron-pyoverdine: Pseudomonas aeruginosa* B Bacteria, 2.73 Å**	2IAH	Data File Jmol Viewer 2IAH	Wirth et al. (2007). Wirth C, Meyer-Klaucke W, Pattus F, & Cobessi D (2007). From the periplasmic signaling domain to the extracellular face of an outer membrane signal transducer of Pseudomonas aeruginosa: crystal structure of the ferric pyoverdine outer membrane receptor. J Mol Biol 368 :398-406. PubMed Id: 17349657.
*AlgE alginate export protein: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.30 Å** 18-stranded β-barrel with a highly electropositive pore constriction that acts as a selectivity filter for negatively charged alginate.	3RBH	Data File Jmol Viewer 3RBH	Whitney et al. (2011). Whitney JC, Hay ID, Li C, Eckford PD, Robinson H, Amaya MF, Wood LF, Ohman DE, Bear CE, Rehm BH, & Lynne Howell P (2011). Structural basis for alginate secretion across the bacterial outer membrane. Proc Natl Acad Sci USA 108 :13083-13088. PubMed Id: 21778407. doi:10.1073/pnas.1104984108.
*AlgE alginate export protein: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 1.90 Å** In meso crystallization. Crystal form 2, 2.80 Å: 4AZL Crystal form 3, 2.40 Å: 4B61	4AFK	Data File Jmol Viewer 4AFK 4B61 4AZL	Tan et al. (2014). Tan J, Rouse SL, Li D, Pye VE, Vogeley L, Brinth AR, El Arnaout T, Whitney JC, Howell PL, Sansom MS, & Caffrey M (2014). A conformational landscape for alginate secretion across the outer membrane of Pseudomonas aeruginosa. Acta Crystallogr D Biol Crystallogr 70 :2054-2068. PubMed Id: 25084326. doi:10.1107/S1399004714001850.
*AlgE alginate export protein at 100 K: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.90 Å** data collected at 293 K, 2.80 Å: 4XNK Structures determined by serial x-ray crystallography	4XNL	Data File Jmol Viewer 4XNL 4XNK	Huang et al. (2015). Huang CY, Olieric V, Ma P, Panepucci E, Diederichs K, Wang M, & Caffrey M (2015). In meso in situ serial X-ray crystallography of soluble and membrane proteins. Acta Crystallogr D Biol Crystallogr 71 :1238-1256. PubMed Id: 26057665. doi:10.1107/S1399004715005210.
*AlgE alginate export protein, native-SAD structure determined at wavelength 2.755 Å: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 1.77 Å** X-ray Structure	8PZ4	Data File Jmol Viewer 8PZ4	El Omari et al. (2023). El Omari K, Duman R, Mykhaylyk V, Orr CM, Latimer-Smith M, Winter G, Grama V, Qu F, Bountra K, Kwong HS, Romano M, Reis RI, Vogeley L, Vecchia L, Owen CD, Wittmann S, Renner M, Senda M, Matsugaki N, Kawano Y, Bowden TA, Moraes I, Grimes JM, Mancini EJ, Walsh MA, Guzzo CR, Owens RJ, Jones EY, Brown DG, Stuart DI, Beis K, & Wagner A (2023). Experimental phasing opportunities for macromolecular crystallography at very long wavelengths. Commun Chem 6 1:219. PubMed Id: 37828292. doi:10.1038/s42004-023-01014-0.
*AlgE alginate export protein in 7.10 monoacylglycerol (MAG): Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 1.45 Å** X-ray structure	8RQP	Data File Jmol Viewer 8RQP	Krawinski et al. (2024). Krawinski P, Smithers L, van Dalsen L, Boland C, Ostrovitsa N, Pérez J, & Caffrey M (2024). 7.10 MAG. A Novel Host Monoacylglyceride for In Meso (Lipid Cubic Phase) Crystallization of Membrane Proteins. Cryst Growth Des 24 7:2985-3001. PubMed Id: 38585376. doi:10.1021/acs.cgd.4c00087.
*AlgK–AlgX alginate export protein complex: Pseudomonas putida* B Bacteria (expressed in E. coli), 2.46 Å**	7ULA	Data File Jmol Viewer 7ULA	Gheorghita et al. (2022). Gheorghita AA, Li YE, Kitova EN, Bui DT, Pfoh R, Low KE, Whitfield GB, Walvoort MTC, Zhang Q, Codée JDC, Klassen JS, & Howell PL (2022). Structure of the AlgKX modification and secretion complex required for alginate production and biofilm attachment in Pseudomonas aeruginosa. Nat Commun 13 1:7631. PubMed Id: 36494359. doi:10.1038/s41467-022-35131-6.
*P pilus usher translocation domain, PapC_130-640: Escherichia coli* B Bacteria, 3.2 Å**	2VQI	Data File Jmol Viewer 2VQI	Remaut et al. (2008). Remaut H, Tang C, Henderson NS, Pinkner JS, Wang T, Hultgren SJ, Thanassi DG, Waksman G, & Li H (2008). Fiber formation across the bacterial outer membrane by the chaperone/usher pathway. Cell 133 :640-652. PubMed Id: 18485872.
*P pilus usher translocation domain, PapC_146-637: Escherichia coli* B Bacteria, 3.15 Å**	3FIP	Data File Jmol Viewer 3FIP	Huang et al. (2009). Huang Y, Smith BS, Chen LX, Baxter RH, & Deisenhofer J (2009). Insights into pilus assembly and secretion from the structure and functional characterization of usher PapC. Proc Natl Acad Sci USA 106 18:7403-7407. PubMed Id: 19380723. doi:10.1073/pnas.0902789106.
*P pilus FimD usher bound to FimC:FimH substrate: Escherichia coli* B Bacteria, 2.80 Å** FimD translocation domain, 3.01 Å: 3OHN	3RFZ	Data File Jmol Viewer 3RFZ 3OHN	Phan et al. (2011). Phan G, Remaut H, Wang T, Allen WJ, Pirker KF, Lebedev A, Henderson NS, Geibel S, Volkan E, Yan J, Kunze MB, Pinkner JS, Ford B, Kay CW, Li H, Hultgren SJ, Thanassi DG, & Waksman G (2011). Crystal structure of the FimD usher bound to its cognate FimC-FimH substrate. Nature 474 :49-53. PubMed Id: 21637253. doi:10.1038/nature10109.
*P pilus FimD usher in complex with FimC:FimF:FimG:FimH: Escherichia coli* B Bacteria, 3.80 Å** This is the complete structure of the tip complex assembly in which the FimC:FimF:FimG:FimH complex passes through FimD.	4J3O	Data File Jmol Viewer 4J3O	Geibel et al. (2013). Geibel S, Procko E, Hultgren SJ, Baker D, & Waksman G (2013). Structural and energetic basis of folded-protein transport by the FimD usher. Nature 496 :243-246. PubMed Id: 23579681. doi:10.1038/nature12007.
*P pilus assembly intermediate (FimD-FimC-FimF-FimG-FimH), conformer 1: Escherichia coli* B Bacteria, 4 Å** cryo-EM structure conformer 2, 5.1 Å: 6E15	6E14	Data File Jmol Viewer 6E14 6E15	Du et al. (2018). Du M, Yuan Z, Yu H, Henderson N, Sarowar S, Zhao G, Werneburg GT, Thanassi DG, & Li H (2018). Handover mechanism of the growing pilus by the bacterial outer-membrane usher FimD. Nature 562 7727:444-447. PubMed Id: 30283140. doi:10.1038/s41586-018-0587-z.
*P pilus tip assembly intermediate PapC-PapD-PapK-PapF-PapG: Escherichia coli* B Bacteria, 7.60 Å** cryo-EM structure PapC-PapD-PapK-PapG in the first conformation, 3.80 Å 7LHG PapC-PapD-PapK-PapG in the second conformation, 7.20 Å 7LHH	7LHI	Data File Jmol Viewer 7LHI 7LHH 7LHG	Du et al. (2021). Du M, Yuan Z, Werneburg GT, Henderson NS, Chauhan H, Kovach A, Zhao G, Johl J, Li H, & Thanassi DG (2021). Processive dynamics of the usher assembly platform during uropathogenic Escherichia coli P pilus biogenesis. Nat Commun 12 1:5207. PubMed Id: 34471127. doi:10.1038/s41467-021-25522-6.
*Transferrin binding protein A (TbpA) in complex with human transferrin: Neisseria meningitidis serogroup b* B Bacteria (expressed in E. coli), 2.60 Å** TbpA in complex with human transferrin C-lobe, 3.10 Å: 3V89 Diferric human transferrin, 2.10 Å: 3V83 Apo-human transferrin C-lobe with bound sulfate ions, 1.70 Å: 3SKP Transferrin binding protein B (TbpB), 2.40 Å: 3V8U	3V8X	Data File Jmol Viewer 3V8X 3V83 3V89 3SKP 3V8U	Noinaj et al. (2012). Noinaj N, Easley NC, Oke M, Mizuno N, Gumbart J, Boura E, Steere AN, Zak O, Aisen P, Tajkhorshid E, Evans RW, Gorringe AR, Mason AB, Steven AC, & Buchanan SK (2012). Structural basis for iron piracy by pathogenic Neisseria. Nature 483 :53-58. PubMed Id: 22327295. doi:10.1038/nature10823.
*Wzi outer-membrane lectin: Escherichia coli* B Bacteria, 2.64 Å** Assists in the formation of the bacterial capsule via direct interaction with capsular polysaccharides.	2YNK	Data File Jmol Viewer 2YNK	Bushell et al. (2013). Bushell SR, Mainprize IL, Wear MA, Lou H, Whitfield C, & Naismith JH (2013). Wzi Is an Outer Membrane Lectin that Underpins Group 1 Capsule Assembly in Escherichia coli. Structure 21 :844-853. PubMed Id: 23623732. doi:10.1016/j.str.2013.03.010.
*Opa₆₀ for receptor-mediated engulfment, EXPLOR refined: Neisseria gonorrhoeae* B Bacteria, NMR strucuture** MD/EXPLOR refined structure, NMR structure: 2MAF	2MLH	Data File Jmol Viewer 2MLH 2MAF	Fox et al. (2014). Fox DA, Larsson P, Lo RH, Kroncke BM, Kasson PM, & Columbus L (2014). Structure of the neisserial outer membrane protein opa60: loop flexibility essential to receptor recognition and bacterial engulfment. J Am Chem Soc 136 :9938-9946. PubMed Id: 24813921. doi:10.1021/ja503093y.
Opa₆₀ for receptor-mediated engulfment, proton-detected magic-angle spinning nuclear magnetic resonance (MAS NMR) used: Neisseria gonorrhoeae B Bacteria (expressed in E. coli), NMR structure	8QWQ	Data File Jmol Viewer 8QWQ	Forster et al. (2024). Forster MC, Tekwani Movellan K, Najbauer EE, Becker S, & Andreas LB (2024). Magic-angle spinning NMR structure of Opa60 in lipid bilayers. J Struct Biol X 9 :100098. PubMed Id: 39010882. doi:10.1016/j.yjsbx.2024.100098.
*CsgG bacterial amyloid secretion channel: Escherichia coli* B Bacteria, 3.59 Å** Pre-pore conformation, 2.80 Å: 4UV2	4UV3	Data File Jmol Viewer 4UV3 4UV2	Goyal et al. (2014). Goyal P, Krasteva PV, Van Gerven N, Gubellini F, Van den Broeck I, Troupiotis-Tsaïlaki A, Jonckheere W, Péhau-Arnaudet G, Pinkner JS, Chapman MR, Hultgren SJ, Howorka S, Fronzes R, & Remaut H (2014). Structural and mechanistic insights into the bacterial amyloid secretion channel CsgG. Nature 516 7530:250-253. PubMed Id: 25219853. doi:10.1038/nature13768.
*CsgG bacterial amyloid secretion channel: Escherichia coli* B Bacteria, 3.10 Å**	4Q79	Data File Jmol Viewer 4Q79	Cao et al. (2014). Cao B, Zhao Y, Kou Y, Ni D, Zhang XC, & Huang Y (2014). Structure of the nonameric bacterial amyloid secretion channel. Proc Natl Acad Sci USA 111 50:E5439-E5444. PubMed Id: 25453093. doi:10.1073/pnas.1411942111.
*CsgG-CsgF complex involved in curli biogenesis: Escherichia coli* B Bacteria, 2.94 Å** cryo-EM structure Low resolution architecture of curli complex, 3.24 Å: 6LQJ curli complex architecture, 3.60 Å: 7BRM	6LQH	Data File Jmol Viewer 6LQH 6LQJ 7BRM	Zhang et al. (2020). Zhang M, Shi H, Zhang X, Zhang X, & Huang Y (2020). Cryo-EM structure of the nonameric CsgG-CsgF complex and its implications for controlling curli biogenesis in Enterobacteriaceae. PLoS Biol 18 6. PubMed Id: 32559189. doi:10.1371/journal.pbio.3000748.
*CsgG-CsgF complex involved in curli biogenesis: Escherichia coli* B Bacteria, 3.38 Å** cryo-EM structure complex with substrate CsgAN6 peptide, 3.34 Å: 6L7C	6L7A	Data File Jmol Viewer 6L7A 6L7C	Yan et al. (2020). Yan Z, Yin M, Chen J, & Li X (2020). Assembly and substrate recognition of curli biogenesis system. Nat Commun 11 1:241. PubMed Id: 31932609. doi:10.1038/s41467-019-14145-7.
*CsgG-CsgF complex involved in curli biogenesis: Escherichia coli* B Bacteria, 3.40 Å** cryo-EM structure	6SI7	Data File Jmol Viewer 6SI7	Van der Verren et al. (2020). Van der Verren SE, Van Gerven N, Jonckheere W, Hambley R, Singh P, Kilgour J, Jordan M, Wallace EJ, Jayasinghe L, & Remaut H (2020). A dual-constriction biological nanopore resolves homonucleotide sequences with high fidelity. Nat Biotechnol 38 12:1415-1420. PubMed Id: 32632300. doi:10.1038/s41587-020-0570-8.
*FusA plant-ferredoxin receptor: Pectobacterium atrosepticum* B Bacteria (expressed in E. coli), 3.2 Å**	4ZGV	Data File Jmol Viewer 4ZGV	Grinter et al. (2016). Grinter R, Josts I, Mosbahi K, Roszak AW, Cogdell RJ, Bonvin AM, Milner JJ, Kelly SM, Byron O, Smith BO, & Walker D (2016). Structure of the bacterial plant-ferredoxin receptor FusA. Nat Commun 7 :13308. PubMed Id: 27796364. doi:10.1038/ncomms13308.
*Omp33 outer membrane protein: Acinetobacter baumannii* B Bacteria (expressed in E. coli), 2.2 Å**	6GIE	Data File Jmol Viewer 6GIE	Abellón-Ruiz et al. (2018). Abellón-Ruiz J, Zahn M, Baslé A, & van den Berg B (2018). Crystal structure of the Acinetobacter baumannii outer membrane protein Omp33. Acta Crystallogr D Struct Biol 74 :852-860. PubMed Id: 30198896. doi:10.1107/S205979831800904X.
*FrpB TonB-dependent iron transporter: Neisseria meningitidis* B Bacteria (expressed in E. coli), 2.40 Å** F5-1 variant, 2.60 Å: 4AIQ F5-1 variant, apo form, 2.32 Å: 4B7O	4AIP	Data File Jmol Viewer 4AIP 4AIQ 4B7O	Saleem et al. (2013). Saleem M, Prince SM, Rigby SE, Imran M, Patel H, Chan H, Sanders H, Maiden MC, Feavers IM, & Derrick JP (2013). Use of a molecular decoy to segregate transport from antigenicity in the FrpB iron transporter from Neisseria meningitidis. PLoS ONE 8 2. PubMed Id: 23457610. doi:10.1371/journal.pone.0056746.
*FhuE TonB-dependent transporter: Escherichia coli* B Bacteria, 2 Å**	6E4V	Data File Jmol Viewer 6E4V	Grinter & Lithgow (2019). Grinter R, & Lithgow T (2019). Determination of the molecular basis for coprogen import by Gram-negative bacteria. IUCrJ 6 :401-411. PubMed Id: 31098021. doi:10.1107/S2052252519002926.
*YncD TonB-dependent transporter: Escherichia coli* B Bacteria, 2.96 Å**	6V81	Data File Jmol Viewer 6V81	Grinter & Lithgow (2020). Grinter R, & Lithgow T (2020). The crystal structure of the TonB-dependent transporter YncD reveals a positively charged substrate-binding site. Acta Crystallogr D Struct Biol 76 :484-495. PubMed Id: 32355044. doi:10.1107/S2059798320004398.
*PfeA ferric enterobactin receptor, apo form: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.12 Å** in complex with enterobactin, 2.7 Å: 6Q5E in complex with azotochelin, 2.78 Å: 5NR2 in complex with protochelin, 2.8 Å: 5NC4 R480A, Q482A mutant, 2.67 Å: 5MZS G324V mutant, 2.9 Å: 5OUT R480A mutant in complex with enterobactin, 3.11 Å: 6R1F Q482A mutant in complex with enterobactin, 2.96 Å: 6I2J	5M9B	Data File Jmol Viewer 5M9B 6R1F 5OUT 6Q5E 5NC4 5NR2 5MZS 6I2J	Moynié et al. (2019). Moynié L, Milenkovic S, Mislin GLA, Gasser V, Malloci G, Baco E, McCaughan RP, Page MGP, Schalk IJ, Ceccarelli M, & Naismith JH (2019). The complex of ferric-enterobactin with its transporter from Pseudomonas aeruginosa suggests a two-site model. Nat Commun 10 1. PubMed Id: 31413254. doi:10.1038/s41467-019-11508-y.
*PfeA ferric enterobactin receptor in complex with TCV: Pseudomonas aeruginosa* E Eukaryota (expressed in E. coli), 2.57 Å** in complex with BCV, 2.71 Å: 6Z33 in complex with TCV-L6, 2.66 Å: 7OBW in complex with TCV_L5, 2.72 Å: 6YY5 in complex with BCV-L6, 3.03 Å: 6Z2N in complex with BCV-L5, 3.04 Å: 6Y47	5NC3	Data File Jmol Viewer 5NC3 7OBW 6Y47 6YY5 6Z33 6Z2N	Moynié et al. (2022). Moynié L, Hoegy F, Milenkovic S, Munier M, Paulen A, Gasser V, Faucon AL, Zill N, Naismith JH, Ceccarelli M, Schalk IJ, & Mislin GLA (2022). Hijacking of the Enterobactin Pathway by a Synthetic Catechol Vector Designed for Oxazolidinone Antibiotic Delivery in Pseudomonas aeruginosa. ACS Infect Dis 8 9:1894-1904. PubMed Id: 35881068. doi:10.1021/acsinfecdis.2c00202.
*BcsC cellulose synthase outer membrane channel: Escherichia coli* B Bacteria, 1.85 Å** See inner membrane components structures: 4HG6	6TZK	Data File Jmol Viewer 6TZK	Acheson et al. (2019). Acheson JF, Derewenda ZS, & Zimmer J (2019). Architecture of the Cellulose Synthase Outer Membrane Channel and Its Association with the Periplasmic TPR Domain. Structure 27 12:1855-1861.e3. PubMed Id: 31604608. doi:10.1016/j.str.2019.09.008.
*ZnuD zinc transporter: Neisseria meningitidis* B Bacteria (expressed in E. coli), 3.20 Å**	4RDT	Data File Jmol Viewer 4RDT	Calmettes et al. (2015). Calmettes C, Ing C, Buckwalter CM, El Bakkouri M, Chieh-Lin Lai C, Pogoutse A, Gray-Owen SD, Pomès R, & Moraes TF (2015). The molecular mechanism of Zinc acquisition by the neisserial outer-membrane transporter ZnuD. Nat Commun 6 :7996. PubMed Id: 26282243. doi:10.1038/ncomms8996.
*MtrE Outer Membrane Channel: Neisseria gonorrhoeae* B Bacteria (expressed in E. coli), 3.29 Å** Multidrug efflux transporter. See 4MT1	4MT0	Data File Jmol Viewer 4MT0	Lei et al. (2014). Lei HT, Chou TH, Su CC, Bolla JR, Kumar N, Radhakrishnan A, Long F, Delmar JA, Do SV, Rajashankar KR, Shafer WM, & Yu EW (2014). Crystal structure of the open state of the Neisseria gonorrhoeae MtrE outer membrane channel. PLoS ONE 9 6. PubMed Id: 24901251. doi:10.1371/journal.pone.0097475.
*LetB lipophilic Envelope-spanning Tunnel B, model 1: Escherichia coli* B Bacteria, 3.46 Å** cryo-EM structure model 2, 3.49 Å: 6V0D model 3, 3.06 Å: 6V0E model 4, 2.96 Å: 6V0F model 5, 3.03 Å: 6V0G model 6, 3.60 Å: 6V0H model 7, 3.43 Å: 6V0I model 8, 3.78 Å: 6V0J domains MCE2-MCE3 by x-ray, 2.15 Å: 6VCI	6V0C	Data File Jmol Viewer 6V0C 6V0E 6VCI 6V0D 6V0G 6V0I 6V0H 6V0J 6V0F	Isom et al. (2020). Isom GL, Coudray N, MacRae MR, McManus CT, Ekiert DC, & Bhabha G (2020). LetB Structure Reveals a Tunnel for Lipid Transport across the Bacterial Envelope. Cell 181 3:653-664.e19. PubMed Id: 32359438. doi:10.1016/j.cell.2020.03.030.
*PcoB copper transporter: Escherichia coli* B Bacteria, 2.00 Å**	7PGE	Data File Jmol Viewer 7PGE	Li et al. (2022). Li P, Nayeri N, Górecki K, Becares ER, Wang K, Mahato DR, Andersson M, Abeyrathna SS, Lindkvist-Petersson K, Meloni G, Missel JW, & Gourdon P (2022). PcoB is a defense outer membrane protein that facilitates cellular uptake of copper. Protein Sci 31 7:e4364. PubMed Id: 35762724. doi:10.1002/pro.4364.
*outer membrane porin OmpW: Klebsiella pneumoniae* B Bacteria (expressed in E. coli), 3.20 Å** X-ray structure	8QXP	Data File Jmol Viewer 8QXP	Seddon et al. (2024). Seddon C, Frankel G, & Beis K (2024). Structure of the outer membrane porin OmpW from the pervasive pathogen Klebsiella pneumoniae. Acta Crystallogr F Struct Biol Commun 80 :22-27. PubMed Id: 38206593. doi:10.1107/S2053230X23010579.
Outer Membrane Autotransporters
*NalP autotransporter translocator domain: Neisseria meningitidis* B Bacteria (expressed in E. coli), 2.60 Å** p6₁22 space group. See also 1UYO, C222₁ space group, 3.2 Å resolution.	1UYN	Data File Jmol Viewer 1UYN 1UYO NaIP translocator domain	Oomen et al. (2004). Oomen CJ, Van Ulsen P, Van Gelder P, Feijen M, Tommassen J, & Gros P (2004). Structure of the translocator domain of a bacterial autotransporter. EMBO J 23 :1257-1266. PubMed Id: 15014442.
*Hia_1022-1098 trimeric autotransporter: Haemophilus influenzae* B Bacteria (expressed in E. coli), 2.0 Å** Hia_992-1098, 2.3 Å: 2GR7	2GR8	Data File Jmol Viewer 2GR8 2GR7 Hia autotransporter	Meng et al. (2006). Meng G, Surana NK, St Geme JW 3rd, Waksman G (2006). Structure of the outer membrane translocator domain of the Haemophilus influenzae Hia trimeric autotransporter. EMBO J 25 :2297-2304. PubMed Id: 16688217.
*EspP autotransporter, post-cleavage state: Escherichia coli* B Bacteria, 2.7 Å**	2QOM	Data File Jmol Viewer 2QOM	Barnard et al. (2007). Barnard TJ, Dautin N, Lukacik P, Bernstein HD, & Buchanan SK (2007). Autotransporter structure reveals intra-barrel cleavage followed by conformational changes. Nature Struc Mol Biol 14 :1214-1220. PubMed Id: 17994105.
*EspP autotransporter, pre-cleavage state (N1023A mutant): Escherichia coli* B Bacteria, 2.48 Å** Pre-cleavage structure (N1023D mutant), 2.52 Å: 3SLO Pre-cleavage structure (N1023S mutant), 2.46 Å: 3SLT	3SLJ	Data File Jmol Viewer 3SLJ 3SLT 3SLO	Barnard et al. (2012). Barnard TJ, Gumbart J, Peterson JH, Noinaj N, Easley NC, Dautin N, Kuszak AJ, Tajkhorshid E, Bernstein HD, & Buchanan SK (2012). Molecular Basis for the Activation of a Catalytic Asparagine Residue in a Self-Cleaving Bacterial Autotransporter. J Mol Biol 415 :128-142. PubMed Id: 22094314. doi:10.1016/j.jmb.2011.10.049.
*EspP autotransporter passenger domain: Escherichia coli* B Bacteria, 2.50 Å** Like a number of other auto-cleaved passengers, a parallel β-helix is a characteristic feature.	3SZE	Data File Jmol Viewer 3SZE	Khan et al. (2011). Khan S, Mian HS, Sandercock LE, Chirgadze NY, & Pai EF (2011). Crystal Structure of the Passenger Domain of the Escherichia coli Autotransporter EspP. J Mol Biol 413 :985-1000. PubMed Id: 21964244. doi:10.1016/j.jmb.2011.09.028.
*AIDA-I autotransport unit (AIDA = adhesin involved in diffuse adherence): Escherichia coli* B Bacteria, 3.00 Å**	4MEE	Data File Jmol Viewer 4MEE	Gawarzewski et al. (2014). Gawarzewski I, DiMaio F, Winterer E, Tschapek B, Smits SHJ, Jose J, & Schmitt L (2014). Crystal structure of the transport unit of the autotransporter adhesin involved in diffuse adherence from Escherichia coli. J Struct Biol 187 1:20-29. PubMed Id: 24841284. doi:10.1016/j.jsb.2014.05.003.
*Hbp (hemoglobin protease) self-cleaving autotransporter with truncated passenger: Escherichia coli* B Bacteria, 2.00 Å** The structure shows the pre-cleavage state.	3AEH	Data File Jmol Viewer 3AEH	Tajima et al. (2010). Tajima N, Kawai F, Park SY, & Tame JR (2010). A novel intein-like autoproteolytic mechanism in autotransporter proteins. J Mol Biol 402 :645-656. PubMed Id: 20615416. doi:10.1016/j.jmb.2010.06.068.
*Hbp (hemoglobin protease) full-length passenger domain: Escherichia coli* B Bacteria, 2.20 Å** The passenger domain has a prominent β-helix domain.	1WXR	Data File Jmol Viewer 1WXR	Otto et al. (2005). Otto BR, Sijbrandi R, Luirink J, Oudega B, Heddle JG, Mizutani K, Park SY, & Tame JR (2005). Crystal structure of hemoglobin protease, a heme binding autotransporter protein from pathogenic Escherichia coli. J Biol Chem 280 :17339-17345. PubMed Id: 15728184. doi:10.1074/jbc.M412885200.
*EstA Autotransporter, full length: Pseudomonas aeruginosa* B Bacteria (expressed in E. coli), 2.50 Å** This is the first full-length structure of an autotransporter. The passenger is not cleaved physiologically, but rather presents an esterase domain to the external world.	3KVN	Data File Jmol Viewer 3KVN	van den Berg (2010). van den Berg B (2010). Crystal Structure of a Full-Length Autotransporter. J Mol Biol 396 :627-633. PubMed Id: 20060837.
*IcsA autotransporter (autochaperone region only): Shigella flexneri* B Bacteria (expressed in E. coli), 2.00 Å**	3ML3	Data File Jmol Viewer 3ML3	Kühnel & Diezmann (2011). Kühnel K & Diezmann D (2011). Crystal structure of the autochaperone region from the Shigella flexneri autotransporter IcsA. J Bacteriol 193 :2042-2045 . PubMed Id: 21335457. doi:10.1128/JB.00790-10.
*Intimin outer membrane β-domain: Escherichia coli* B Bacteria, 1.86 Å** The C-terminal passenger domain, not present in this structure, is involved in adhesion to host cells.	4E1S	Data File Jmol Viewer 4E1S	Fairman et al. (2012). Fairman JW, Dautin N, Wojtowicz D, Liu W, Noinaj N, Barnard TJ, Udho E, Przytycka TM, Cherezov V, & Buchanan SK (2012). Crystal structures of the outer membrane domain of intimin and invasin from enterohemorrhagic E. coli and enteropathogenic Y. pseudotuberculosis. Structure 20 :1233-1243. PubMed Id: 22658748. doi:10.1016/j.str.2012.04.011.
*Intimin C-terminal passenger domain in complex with receptor: Escherichia coli* B Bacteria, 2.90 Å**	1F02	Data File Jmol Viewer 1F02	Luo et al. (2000). Luo Y, Frey EA, Pfuetzner RA, Creagh AL, Knoechel DG, Haynes CA, Finlay BB, & Strynadka NC (2000). Crystal structure of enteropathogenic Escherichia coli intimin-receptor complex. Nature 405 :1073-1077. PubMed Id: 10890451. doi:10.1038/35016618. See also: Batchelor et al. (2000). Batchelor M, Prasannan S, Daniell S, Reece S, Connerton I, Bloomberg G, Dougan G, Frankel G, & Matthews S (2000). Structural basis for recognition of the translocated intimin receptor (Tir) by intimin from enteropathogenic Escherichia coli. EMBO J 19 :2452-2464. PubMed Id: 10835344.
*Invasin outer membrane β-domain: Yersinia pseudotuberculosis* B Bacteria (expressed in E. coli), 2.26 Å** The C-terminal passenger domain, not present in this structure, is involved in adhesion to host cells.	4E1T	Data File Jmol Viewer 4E1T	Fairman et al. (2012). Fairman JW, Dautin N, Wojtowicz D, Liu W, Noinaj N, Barnard TJ, Udho E, Przytycka TM, Cherezov V, & Buchanan SK (2012). Crystal structures of the outer membrane domain of intimin and invasin from enterohemorrhagic E. coli and enteropathogenic Y. pseudotuberculosis. Structure 20 :1233-1243. PubMed Id: 22658748. doi:10.1016/j.str.2012.04.011.
*Invasin C-terminal passenger domain: Yersinia pseudotuberculosis* B Bacteria (expressed in E. coli), 2.30 Å**	1CWV	Data File Jmol Viewer 1CWV	Hamburger et al. (1999). Hamburger ZA, Brown MS, Isberg RR, & Bjorkman PJ (1999). Crystal structure of invasin: a bacterial integrin-binding protein. Science 286 :291-295. PubMed Id: 10514372.
*YadA trimeric adhesin autotransporter: Yersinia enterocolitica subsp. enterocolitica 8081* B Bacteria (expressed in E. coli), NMR Structure** Structure determined from microcrystals using solid-state NMR	2LME	Data File

from the Stephen White laboratory at UC Irvine

and the Bridge Institute at USC

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