TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
1.B.6.1.1









Weakly anion-selective OmpA porin.  Can exist in two distinct conductance states (Arora et al. 2000).  May function in the transport of phenylpropanoids (resveratrol, naringenin and rutin) (Zhou et al. 2014). Three membrane-bound folding intermediates of OmpA were discovered in folding studies with dioleoylphosphatidylcholine bilayers. A highly synchronized mechanism of secondary and tertiary structure formation, applicable to this and other β-barrel membrane proteins has been described (Kleinschmidt 2006).

Bacteria
Pseudomonadota
OmpA of E. coli (P0A910)
1.B.6.1.2









OmpF (OprF) porin.  The N-terminal domain has pore activity (Saint et al. 2000).  The protein can exist in multiple conformations of variable conductivities (Nestorovich et al. 2006).  Factors affecting its one-domain open conformer have been studied by Sugawara et al. (2010). OprF is a complement component C3 receptor (Mishra et al. 2015) and is a target of antibacterial drugs (Maccarini et al. 2017). OprF assumes dual conformations and is involved in solute transport, cell envelope integrity, biofilm formation and pathogenesis (Cassin and Tseng 2019). OprF in Pseudomonas aeruginosa is involved in biofilm stimulation by subinhibitory antibiotics (Yaeger et al. 2024).

Bacteria
Pseudomonadota
OmpF (OprF) of Pseudomonas aeruginosa (P13794)
1.B.6.1.3









OmpATb (ArfA). The central domain (residues 73-220) has been reported to exhibit channel activity (Molle et al., 2006). Its expression is dependent on small single TMS membrane proteins which are encoded in a single operon with it (Veyron-Churlet et al., 2011). The rv0899 gene, encoding OmpATb, is part of an operon (rv0899-rv0901) that is required for fast ammonia secretion, pH neutralization, and growth of M. tuberculosis in acidic environments (Song et al. 2011). Homologues are widespread in bacteria with functions in nitrogen metabolism, adaptation to nutrient poor environments, and/or establishing symbiosis with host organisms (Marassi, 2011). The high resolution 3-d structure is known, revealing two independent domains separated by a proline-rich hinge region.The C-terminal domain (OmpATb(198-326)) revealed a module structurally related to other OmpA-like proteins from Gram-negative bacteria, but the N-terminal domain(73-204), which  forms channels in planar lipid bilayers, exhibits a fold, which belongs to the α+β sandwich class fold. It exists in a major monomeric form and a minor oligomeric form yielding rings able to insert into phospholipid membranes (Yang et al. 2011). 

Bacteria
Actinomycetota
OmpATb of Mycobacterium tuberculosis (P65593)
1.B.6.1.4









HMP-AB outer membrane porin, OmpAb or Omp38 (Gribun et al., 2004).  It is the principle porin with an inner diameter of 2 nm which allows transport of cephalothin, cephaloridine, other antibiotics as well as other small molecules across the outer membrane (Sugawara and Nikaido 2012). Structural studies have been reported (Vashist and Rajeswari 2006). It is a secreted emulifier in some strains of Acinetobacter (Walzer et al. 2006). The sequence provided may be slightly incorrect (see the Q6BYW5 sequence of 356 aas).

Bacteria
Pseudomonadota
HMP-AB of Acinetobacter baumannii (Q8KWW6)
1.B.6.1.5









The OmpA-OmpF porin (OOP) family member, GmpA (involved in acetic acid fermentation; under quorum sensing control) (Iida et al., 2008). (most similar to 1.B.6.1.4)

Bacteria
Pseudomonadota
GmpA of Gluconacetobacter intermedius (B3A000)
1.B.6.1.6









Outer membrane protein 40 (Omp40) (PG33)
Bacteria
Bacteroidota
PG_0694 of Porphyromonas gingivalis
1.B.6.1.7









OmpA homologue

Bacteria
Bacillota
OmpA homologue of Megasphaera elsdenii
1.B.6.1.8









OmpA homologue

Bacteria
Bacillota
OmpA homologue of Megasphaera sp. UPII 135-E
1.B.6.1.9









OMP_b-br1 family protein

Bacteria
Bacillota
Outer membrane protein of Megasphaera elsdenii
1.B.6.1.10









Outer membrane insertion signal domain protein of 190 aas and one N-terminal TMS.  An ortholog in Veillonella parvula is 84% identical, and was considered to be a porin by Poppleton et al. 2017.

Bacteria
Bacillota
OMISD protein of Veillonella atypica
1.B.6.1.11









OmpA of 210 aas. The 3-d structure has been solved by NMR (Renault et al. 2010), and its dynamics have been examined (Renault et al. 2009).

Bacteria
Pseudomonadota
OmpA of Klebsiella pneumoniae
1.B.6.1.12









Omp34 outer membrane porin of 346 aas.  Also known as the Major antigen Fc binding protein (White et al. 1998).

Bacteria
Pseudomonadota
Omp34 of Aggregatibacter actinomycetemcomitans (Actinobacillus actinomycetemcomitans) (Haemophilus actinomycetemcomitans)
1.B.6.1.13









Putative porin of 253 aas

Bacteria
Actinomycetota
Putative porin of Nocardioidaceae bacterium Broad-1
1.B.6.1.14









Outer membrane protein of 638 aas, OmpF

Bacteria
Bacteroidota
OmpF of Cecembia lonarensis
1.B.6.1.15









OmpA/F

Bacteria
Spirochaetota
OmpA/F of Treponema pallidum
1.B.6.1.16









OmpA family porin of 410 aas

Bacteria
Pseudomonadota
OmpA porin of Phenylobacterium zucineum
1.B.6.1.17









Putative OmpF homologue

Bacteria
Spirochaetota
Putative OmpF homologue of Leptospira interrogans
1.B.6.1.18









Outer membrane protein of 210 aas and 8 putative TMSs

Bacteria
Pseudomonadota
OMP of Thiothrix nivea
1.B.6.1.19









Outer membrane protein of 218 aas and 8 putative TMSs

Bacteria
Bacteroidota
OMP of Mariniradius saccharolyticus
1.B.6.1.20









OmpA homologue of 189 aas

Bacteria
Spirochaetota
OmpA homologue of Leptospira biflexa
1.B.6.1.21









OmpA-type porin of 160 aas, YfiB The yfiRNB locus in E. coli CFT073 contains genes for YfiN, a diguanylate cyclase, and its activity regulators, YfiR and YfiB.(Raterman et al. 2013).

Bacteria
Pseudomonadota
YfiB of E. coli
1.B.6.1.22









Constitutively expressed OmpA of 365 aas (Gao et al. 2015).

Bacteria
Pseudomonadota
OmpA of Shewanella oneidensis
1.B.6.1.23









OmpA of 354 aas with 1 N-terminal α-TMS, 10 putative β-TM Strands and a periplasmic C-terminal domain, probably a peptidoglycan-binding domain (Khalid et al. 2008).  Plays a role in virulence (pneumonia in pigs and ruminants) (Verma et al. 2016; Confer and Ayalew 2013) and has been used for vaccine development (Dabo et al. 2008).

Bacteria
Pseudomonadota
OmpA of Pasteurella multocida
1.B.6.1.24









Omp38; OmpA of 356 aas and 1 N-terminal TMSs. It is a selective antibiotic transporting porin (Iyer et al. 2018; Jyothisri et al. 1999) and induces apoptosis in human cell lines through caspase-dependent and AIF-dependent pathways. Purified Omp38 enters host cells and localizes to the mitochondria, which presumably leads to a release of proapoptotic molecules such as cytochrome c and AIF (apoptosis-inducing factor) (Choi et al. 2005). It is a virulence factor (Scribano et al. 2024).

Bacteria
Pseudomonadota
omp38 of Acinetobacter baumannii
1.B.6.1.25









Putative OmpA porin of 345 aas and one N-terminal TMS. Its gene is adjacent to an autoinducer exporter-like protein (2.A.86.1.11) (Poppleton et al. 2017).

Bacteria
Bacillota
OmpA-like protein of Veillonella parvula
1.B.6.1.26









OmpA -like protein of 159 aas and 1 N-terminal TMS, PsaB or YfiB.  It is involved in stress tolerance (Scribano et al. 2024). 

Bacteria
Pseudomonadota
PsaB of Acinetobacter baumannii
1.B.6.2.1









Outer membrane porin precursor, OmpX (8 TM β-strands). The NMR structures in lipid bilayers has been solved (Mahalakshmi et al., 2007; Mahalakshmi and Marassi, 2008; Fernández et al. 2004). Expression of the encoding gene is induced by acid or base compared to pH 7 (Stancik et al. 2002).

Bacteria
Pseudomonadota
OmpX of E. coli (P0A917)
1.B.6.2.2









The attachment inversion locus (Ail) (Bartra et al., 2007).  Membrane-bound proteins, Ail and OmpF, are involved in the adsorption of T7-related bacteriophage (Zhao et al. 2013).

Bacteria
Pseudomonadota
Ail of Yersinia pestis (Q0WCZ9)
1.B.6.2.3









Opacity family porin protein
Bacteria
Pseudomonadota
UMN179_00549 of Gallibacterium anatis
1.B.6.2.4









Opacity family porin protein
Bacteria
Pseudomonadota
UMN179_00948 of Gallibacterium anatis
1.B.6.2.5









Neisserial surface protein A, NspA of 174 aas and 8 TMSs (Hou et al. 2003).

Bacteria
Pseudomonadota
NspA of Neisseria meningitidis
1.B.6.2.6









Porin opacity type
Bacteria
Pseudomonadota
AM202_02155 of Actinobacillus minor 202
1.B.6.2.7









Outer membrane porin homolog, but annotated as arginine transporter permease subunit, ArtM, in Uniprot.

Bacteria
Pseudomonadota
GGC_0882 of Haemophilus haemolyticus M21621
1.B.6.2.8









Opa-like protein A
Bacteria
Pseudomonadota
E9U_09445 of Moraxella catarrhalis BC8
1.B.6.2.9









Surface protein A
Bacteria
Pseudomonadota
NspA of Neisseria wadsworthii 9715
1.B.6.2.10









Outer membrane porin, OmpX of 171 aas (Dupont et al. 2004).

Bacteria
Pseudomonadota
OmpX of Enterobacter (Aerobacter) aerogenes
1.B.6.2.11









Outer membrane porin, opacity type, of 189 aas

Bacteria
Chlorobiota
OMP of Prosthecochloris vibrioformis
1.B.6.2.12









Outer membrane porin, opacity type, of 230 aas

Bacteria
Chlorobiota
OMP of Chlorobaculum parvum
1.B.6.2.13









Putative invasin of 242 aas

Bacteria
Pseudomonadota
Putative invasin of E. coli
1.B.6.2.14









Uncharacterized protein of 290 aas

Bacteria
Pseudomonadota
UP of Nitrobacter hamburgensis
1.B.6.2.15









Putative porin of 199 aas

Bacteria
Pseudomonadota
Putative porin of Rhodanobacter thiooxydans
1.B.6.2.16









Uncharacterized protein of 196 aas

Bacteria
Pseudomonadota
UP of Vibrio fischeri
1.B.6.2.17









Putative porin of 195 aas

Bacteria
Pseudomonadota
Putative porin of Vibrio alginolyticus
1.B.6.2.18









Uncharacterized protein of 186 aas

Bacteria
Pseudomonadota
UP of Agarivorans albus
1.B.6.2.19









Putative porin of 182 aas

Bacteria
Pseudomonadota
PP of Grimontia hollisae
1.B.6.2.20









Ail/Lom protein of 199 aas

Bacteria
Pseudomonadota
Ail/Lom protein of E. coli
1.B.6.3.1









Putative porin of 197 aas

Bacteria
Verrucomicrobiota
PP of Opitutaceae bacterium TAV1
1.B.6.3.2









Putative porin of 277 aas

Bacteria
Verrucomicrobiota
PP of Coraliomargarita sp. CAG:312
1.B.6.3.3









Putative porin

Bacteria
Verrucomicrobiota
PP of Opitutus terrae
1.B.6.4.1









Putative porin of 183 aas

Bacteria
Pseudomonadota
Putative porin of Vibrio parahaemolyticus
1.B.6.4.2









Porin of 190 aas and 1 N-terminal TMS.

Bacteria
Pseudomonadota
Porin of Shewanella psychrophila
1.B.6.4.3









Porin of 198 aas and 1 N-terminal TMS.

Bacteria
Pseudomonadota
Porin of Pseudoalteromonas luteoviolacea
1.B.6.4.4









Porin of 180 aas and 1 N-terminal TMS

Bacteria
Pseudomonadota
Porin of Vibrio caribbeanicus
1.B.6.4.5









Porin of 186 aas and 1 N-terminal TMS

Bacteria
Pseudomonadota
Porin of Litorilituus sp. RZ04
1.B.6.5.1









Outer membrane protein of 205 aas and 8 putative TMSs.

Bacteria
Fibrobacterota
OMP of Fibrobacter succinogens
1.B.6.5.2









Outer membrane protein of 197 aas and 8 putative TMSs.

Bacteria
Fibrobacterota
OMP of Fibrobacter succinogenes
1.B.6.5.3









Outer membrane protein of 534 aas and 6 - 22 beta strands.

Bacteria
Spirochaetota
OMP of Turneriella parva
1.B.6.5.4









Outer membrane protein of 211 aas and 8 beta strands.

Bacteria
Myxococcota
OMP of Myxococcus xanthus
1.B.6.5.5









Outer membrane protein of 201 aas and 9 putative beta strands.

Bacteria
Pseudomonadota
OMP of Vibrio tubiashii
1.B.6.5.6









Outer membrane protein, OmpA of 196 aas and 8 putative TMSs

Bacteria
Pseudomonadota
OmpA of Aliivibrio salmonicida
1.B.6.6.1









Outer membrane protein of 201 aas and 8 putative β-TMSs.

Bacteria
Bacteroidota
OMP of Cyclobacterium marinum
1.B.6.6.2









Outer membrane protein of 224 aas and 8 TMSs

Bacteria
Bacteroidota
OMP of Dyadobacter fermentans
1.B.6.6.3









Outer membrane protein of 204 aas and 8 TMSs

Bacteria
Bacteroidota
OMP of Solitalea canadensis
1.B.6.6.4









Outer membrane protein of 221 aas and 8 TMSs

Bacteria
Bacteroidota
OMP of Psychroflexus torquis
1.B.6.6.5









Outer membrane protein of 222 aas

Bacteria
Bacteroidota
OMP of Echinicola vietnamensis
1.B.6.6.6









Outer membrane protein of 199 aas

Bacteria
Bacteroidota
OMP of Chitinophaga pinensis
1.B.6.6.7









Porin of 193 aas and 8 beta strands

Bacteria
Bacteroidota
Porin of Flavobacterium johnsoniae
1.B.6.6.8









Porin of 180 aas and 8 beta strands

Bacteria
Nitrospirota
Porin of Candidatus Nitrospira defluvii
1.B.6.6.9









Porin of 207 aas and 8 beta strands

Bacteria
Myxococcota
Porin of Myxococcus xanthus
1.B.6.6.10









Putative porin of 157 aas and 8 beta strands

Bacteria
Bacteroidota
Putative porin of Paludibacter propionicigenes
1.B.6.6.11









Uncharacterized protein of 208 aas.

Bacteria
Bacteroidota
UP of Pedobacter saltans
1.B.6.6.12









Putative porin of 192 aas

Bacteria
Bacteroidota
Putative porin of Capnocytophaga sputigena
1.B.6.7.1









Outer membrane protein of 257 aas and 8 beta strands

Bacteria
Bacteroidota
OMP of Bacteroides fragilis
1.B.6.7.2









Porin of 275 aas and 1 N-terminal TMS

Bacteria
Bacteroidota
Porin of Bacteroides xylanisolvens
1.B.6.7.3









DUF4421 domain-containing protein of 334 aas and 1 N-terminal TM

Bacteria
Bacteroidota
Putative porin of Flavobacterium rivuli
1.B.6.8.1









Porin of 224 aas and 8 beta strands, TtoA (Estrada Mallarino et al. 2015).  The crystal structure is known (3DZM) (Nesper et al. 2008). The 2.8 Å structure reveals a transmembrane 8 stranded β-barrel, an extracellular cation-binding region and an external 5-β stranded sheet (Brosig et al. 2009).

Bacteria
Deinococcota
Porin of Thermus thermophilus
1.B.6.8.2









Putative porin of 222 aas.

Bacteria
Deinococcota
Putative porin of Deinococcus geothermalis
1.B.6.8.3









Putative porin of 227 aas and 1 N-terminal TMS

Bacteria
Ignavibacteriota
Porin of Ignavibacterium album
1.B.6.9.1









Uncharacterized protein of 186 aas.

Bacteria
Ignavibacteriota
UP of Ignavibacterium album
1.B.6.9.2









Uncharacterized putative porin protein of 189 aas.

Bacteria
Bacteroidota
UP of Owenweeksia hongkongensis
1.B.6.9.3









Uncharacterized putative porin of 205 aas

Bacteria
Bacteroidota
Putative porin of Owenweeksia hongkongensis
1.B.6.9.4









Uncharacterized protein of 167 aas

Bacteria
Bacteroidota
UP of Elizabethkingia anophelis
1.B.6.10.1









Putative OmpW homologue of 219 aas (Giacani et al. 2015).

Bacteria
Spirochaetota
Putative OmpW homologue of Treponema pallidum
1.B.6.10.2









Putative OmpW homologue of 291 aas (Giacani et al. 2015).

Bacteria
Spirochaetota
Putative OmpW homologue of Treponema pallidum
1.B.6.10.3









Putative OmpW porin of 211 aas and 8 β-strands

Bacteria
Spirochaetota
Putative OmpW homologue of Treponema azotonutricium
1.B.6.10.4









Putative OmpW homologue of 206 aas and 8 β-strands.

Bacteria
Spirochaetota
Putative OmpW homologue of Spirochaeta africana
1.B.6.10.5









Putative OmpW homologue of 211 aas

Bacteria
Spirochaetota
OmpW homologue of Borrelia hermsii
1.B.6.10.6









Uncharacterized protein of 196 aas.

Bacteria
Spirochaetota
UP of Sphaerochaeta pleomorpha
1.B.6.10.7









Uncharacterized protein of 205 aas.

Bacteria
Spirochaetota
UP of Treponema denticola
1.B.6.11.1









Putative porin of 357 aas and 1 N-terminal TMS

Archaea
Euryarchaeota
Porin of Candidatus Methanoperedenaceae archaeon
1.B.6.11.2









Uncharacterized protein of 407 aas

Ciliophora
UP of Stentor coeruleus
1.B.6.12.1









A major outer membrane protein of 298 aas and 1 N-terminal TMS, from Methylacidiphilum fumariolicum SolV (Liu et al. 2023). This porin has a β-barrel structure consisting of ten antiparallel β-sheets and with a small amphipathic N-terminal α-helix in the periplasm. Because M. fumariolicum SolV, lives in a geothermal environment with low pH and high temperatures, this protein may act as barrier to resist the extreme conditions found in its natural environment (Liu et al. 2023).

Bacteria
Verrucomicrobiota
Major OM Porin, WP_009059494, of Methylacidiphilum fumariolicum SolV
1.B.6.12.2









Uncharacterized opacity protein or related surface antigen of 278 aas and 1 N-terminal TMS.  This protein is also distantly related to members of TC family 1.B.49.

Bacteria
Planctomycetota
UP of a Bradyrhizobium sp. S23321 [Gemmataceae bacterium]
1.B.6.12.3









Outer membrane beta-barrel protein of 306 aas and 1 N-terminal TMS. This protein resembles members of TC family 1.B.49. a member of theOMPP1 Superfamily.

Bacteria
Verrucomicrobiota
OMP of Candidatus Methylacidithermus pantelleriae
1.B.6.13.1









Putative lipoprotein, YiaD, of 219 aas with 3 N-terminal TMSs and a C-terminla OmpA peptidoglycan binding domain. When expressed in a multicopy plasmid, its expression supressed the phenotype of a bamD ts mutant (Tachikawa and Kato 2011).

Bacteria
Pseudomonadota
YiaD of E. coli
1.B.6.13.2









Uncharacterized protein of 212 aas and 3 N-terminal TMSs plus a C-terminal OmpA peptidoglycan binding domain.

Bacteria
Fusobacteriota
UP of Fusobacterium periodonticum
1.B.6.13.3









Uncharacterized protein of 226 aas with 3 N-terminal TMSs and a C-terminal OmpA domain.

Bacteria
Bacteroidota
UP of Prevotella ruminicola
1.B.6.13.4









Putative uncharacterized porin of 368 aas

Bacteria
Bdellovibrionota
UP of Bdellovibrio bacteriovorus
1.B.6.13.5









ArfA, a member of the OmpA family.  It is of 471 aas with 3 N-terminal TMSs.  It affects cell stiffness, cell shape and virulence (Scribano et al. 2024).

Bacteria
Pseudomonadota
ArfA of Acinetobacter baumannii