pfam06439, DUF1080, Domain of Unknown Function (DUF1080). This family has structural similarity to an endo-1,3-1,4-beta glucanase belonging to glycoside hydrolase family 16. However, the structure surrounding the active site differs from that of the endo-1,3-1,4-beta glucanase.
cd01299, Met_dep_hydrolase_A, Metallo-dependent hydrolases, subgroup A is part of the superfamily of metallo-dependent hydrolases, a large group of proteins that show conservation in their 3-dimensional fold (TIM barrel) and in details of their active site. The vast majority of the members have a conserved metal binding site, involving four histidines and one aspartic acid residue. In the common reaction mechanism, the metal ion (or ions) deprotonate a water molecule for a nucleophilic attack on the substrate. The function of this subgroup is unknown.
cd05250, CC3_like_SDR_a, CC3(TIP30)-like, atypical (a) SDRs. Atypical SDRs in this subgroup include CC3 (also known as TIP30) which is implicated in tumor suppression. Atypical SDRs are distinct from classical SDRs. Members of this subgroup have a glycine rich NAD(P)-binding motif that resembles the extended SDRs, and have an active site triad of the SDRs (YXXXK and upstream Ser), although the upstream Asn of the usual SDR active site is substituted with Asp. For CC3, the Tyr of the triad is displaced compared to the usual SDRs and the protein is monomeric, both these observations suggest that the usual SDR catalytic activity is not present. NADP appears to serve an important role as a ligand, and may be important in the interaction with other macromolecules. Atypical SDRs generally lack the catalytic residues characteristic of the SDRs, and their glycine-rich NAD(P)-binding motif is often different from the forms normally seen in classical or extended SDRs. Atypical SDRs include biliverdin IX beta reductase (BVR-B,aka flavin reductase), NMRa (a negative transcriptional regulator of various fungi), progesterone 5-beta-reductase like proteins, phenylcoumaran benzylic ether and pinoresinol-lariciresinol reductases, phenylpropene synthases, eugenol synthase, triphenylmethane reductase, isoflavone reductases, and others. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold, an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Sequence identity between different SDR enzymes is typically in the 15-30% range; they catalyze a wide range of activities including the metabolism of steroids, cofactors, carbohydrates, lipids, aromatic compounds, and amino acids, and act in redox sensing. Classical SDRs have an TGXXX[AG]XG cofactor binding motif and a YXXXK active site motif, with the Tyr residue of the active site motif serving as a critical catalytic residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase numbering). In addition to the Tyr and Lys, there is often an upstream Ser and/or an Asn, contributing to the active site; while substrate binding is in the C-terminal region, which determines specificity. The standard reaction mechanism is a 4-pro-S hydride transfer and proton relay involving the conserved Tyr and Lys, a water molecule stabilized by Asn, and nicotinamide. In addition to the Rossmann fold core region typical of all SDRs, extended SDRs have a less conserved C-terminal extension of approximately 100 amino acids, and typically have a TGXXGXXG cofactor binding motif. Complex (multidomain) SDRs such as ketoreductase domains of fatty acid synthase have a GGXGXXG NAD(P)-binding motif and an altered active site motif (YXXXN). Fungal type ketoacyl reductases have a TGXXXGX(1-2)G NAD(P)-binding motif.
pfam01261, AP_endonuc_2, Xylose isomerase-like TIM barrel. This TIM alpha/beta barrel structure is found in xylose isomerase and in endonuclease IV (EC:3.1.21.2). This domain is also found in the N termini of bacterial myo-inositol catabolism proteins. These are involved in the myo-inositol catabolism pathway, and is required for growth on myo-inositol in Rhizobium leguminosarum bv. viciae.
pfam14362, DUF4407, Domain of unknown function (DUF4407). This family of proteins is found in bacteria. Proteins in this family are typically between 366 and 597 amino acids in length. There is a single completely conserved residue R that may be functionally important.
pfam06439, DUF1080, Domain of Unknown Function (DUF1080). This family has structural similarity to an endo-1,3-1,4-beta glucanase belonging to glycoside hydrolase family 16. However, the structure surrounding the active site differs from that of the endo-1,3-1,4-beta glucanase.
NF033201, Vip_LPXTG_Lm, cell invasion LPXTG protein Vip. Vip (Virulence protein), like the LPXTG-type internalins, is an LPXTG-anchored surface protein of the mammalian cell-invading pathogen Listeria monocytogenes, but absent from the related species Listeria innocua. For certain cell types, Vip is required for Listeria's ability to invade. It appears to bind the endoplasmic reticulum (ER) resident chaperone Gp96 as its receptor.
pfam03544, TonB_C, Gram-negative bacterial TonB protein C-terminal. The TonB_C domain is the well-characterized C-terminal region of the TonB receptor molecule. This protein is bound to an inner membrane-bound protein ExbB via a globular domain and has a flexible middle region that is likely to help in positioning the C-terminal domain into the iron-transporter barrel in the outer membrane. TonB_C interacts with the N-terminal TonB box of the outer membrane transporter that binds the Fe3+-siderophore complex. The barrel of the transporter, consisting of 22 beta-sheets and an inside plug, binds the iron complex in the barrel entrance.
pfam07980, SusD_RagB, SusD family. This domain is found in bacterial cell surface proteins such SusD and SusD-like proteins, as as well RagB, outer membrane surface receptor antigen. Bacteroidetes, one of the two dominant bacterial phyla in the human gut, are Gram-negative saccharolytic microorganisms that utilize a diverse array of glycans. Hence, they express starch-utilization system (Sus) for glycan uptake. SusD has 551 amino acids, and is almost entirely alpha-helical, with 22 alpha-helices, eight of which form 4 tetra-trico peptide repeats (TPRs: helix-turn-helix motifs involved in protein-protein interactions). The four TPRs pack together to create a right-handed super-helix. This is predicted to mediate the formation of SusD and SusC porin complex at the cell surface. The interaction between SusC and TPR1/TPR2 region of SusD is predicted to be of functional importance since it allows SusD to be in position for oligosaccharide capture from other Sus lipoproteins and delivery of these glycans to the SusC porin. The non-TPR containing portion of SusD is where starch binding occurs. The binding site is a shallow surface cavity located on top of TPR1. SusD homologs such as SusD-like proteins have a critical role in carbohydrate acquisition. Both SusD and its homologs, contain about 15-20 residues at the N-terminus that might be a flexible linker region, anchoring the protein to the membrane and the glycan-binding domain. Other homologs to SusD have been examined in Porphyromonas gingivalis such as RagB, an immunodominant outer-membrane surface receptor antigen. Structural characterization of RagB shows substantial similarity with Bacteroides thetaiotaomicron SusD (i.e alpha-helices and TPR regions). Based on this structural similarity, functional studies suggest that, RagB binding of glycans occurs at pockets on the molecular surface that are distinct from those of SusD.
pfam02515, CoA_transf_3, CoA-transferase family III. CoA-transferases are found in organisms from all lines of descent. Most of these enzymes belong to two well-known enzyme families, but recent work on unusual biochemical pathways of anaerobic bacteria has revealed the existence of a third family of CoA-transferases. The members of this enzyme family differ in sequence and reaction mechanism from CoA-transferases of the other families. Currently known enzymes of the new family are a formyl-CoA: oxalate CoA-transferase, a succinyl-CoA: (R)-benzylsuccinate CoA-transferase, an (E)-cinnamoyl-CoA: (R)-phenyllactate CoA-transferase, and a butyrobetainyl-CoA: (R)-carnitine CoA-transferase. In addition, a large number of proteins of unknown or differently annotated function from Bacteria, Archaea and Eukarya apparently belong to this enzyme family. Properties and reaction mechanisms of the CoA-transferases of family III are described and compared to those of the previously known CoA-transferases.
TIGR04056, OMP_RagA_SusC, TonB-linked outer membrane protein, SusC/RagA family. This model describes a distinctive clade among the TonB-linked outer membrane proteins (OMP). Members of this family are restricted to the Bacteriodetes lineage (except for Gemmatimonas aurantiaca T-27 from the novel phylum Gemmatimonadetes) and occur in high copy numbers, with over 100 members from Bacteroides thetaiotaomicron VPI-5482 alone. Published descriptions of members of this family are available for RagA from Porphyromonas gingivalis, SusC from Bacteroides thetaiotaomicron, and OmpW from Bacteroides caccae. Members form pairs with members of the SusD/RagB family (pfam07980). Transporter complexes including these outer membrane proteins are likely to import large degradation products of proteins (e.g. RagA) or carbohydrates (e.g. SusC) as nutrients, rather than siderophores. [Transport and binding proteins, Unknown substrate].
pfam12684, DUF3799, PDDEXK-like domain of unknown function (DUF3799). This family of proteins is functionally uncharacterized. This family of proteins is found in bacteria and viruses. Proteins in this family are typically between 265 and 420 amino acids in length. It appears that these proteins are distantly related to the PDDEXK superfamily and so these domains are likely to be nucleases. This family has a C-terminal cysteine cluster similar to that found in pfam01930.
pfam03200, Glyco_hydro_63, Glycosyl hydrolase family 63 C-terminal domain. This is a family of eukaryotic enzymes belonging to glycosyl hydrolase family 63. They catalyze the specific cleavage of the non-reducing terminal glucose residue from Glc(3)Man(9)GlcNAc(2). Mannosyl oligosaccharide glucosidase EC:3.2.1.106 is the first enzyme in the N-linked oligosaccharide processing pathway. This family represents the C-terminal catalytic domain.
TIGR02937, RNA_polymerase_sigma_factor, RNA polymerase sigma factor, sigma-70 family. This model encompasses all varieties of the sigma-70 type sigma factors including the ECF subfamily. A number of sigma factors have names with a different number than 70 (i.e. sigma-38), but in fact, all except for the Sigma-54 family (TIGR02395) are included within this family. Several Pfam models hit segments of these sequences including Sigma-70 region 2 (pfam04542) and Sigma-70, region 4 (pfam04545), but not always above their respective trusted cutoffs.
pfam07980, SusD_RagB, SusD family. This domain is found in bacterial cell surface proteins such SusD and SusD-like proteins, as as well RagB, outer membrane surface receptor antigen. Bacteroidetes, one of the two dominant bacterial phyla in the human gut, are Gram-negative saccharolytic microorganisms that utilize a diverse array of glycans. Hence, they express starch-utilization system (Sus) for glycan uptake. SusD has 551 amino acids, and is almost entirely alpha-helical, with 22 alpha-helices, eight of which form 4 tetra-trico peptide repeats (TPRs: helix-turn-helix motifs involved in protein-protein interactions). The four TPRs pack together to create a right-handed super-helix. This is predicted to mediate the formation of SusD and SusC porin complex at the cell surface. The interaction between SusC and TPR1/TPR2 region of SusD is predicted to be of functional importance since it allows SusD to be in position for oligosaccharide capture from other Sus lipoproteins and delivery of these glycans to the SusC porin. The non-TPR containing portion of SusD is where starch binding occurs. The binding site is a shallow surface cavity located on top of TPR1. SusD homologs such as SusD-like proteins have a critical role in carbohydrate acquisition. Both SusD and its homologs, contain about 15-20 residues at the N-terminus that might be a flexible linker region, anchoring the protein to the membrane and the glycan-binding domain. Other homologs to SusD have been examined in Porphyromonas gingivalis such as RagB, an immunodominant outer-membrane surface receptor antigen. Structural characterization of RagB shows substantial similarity with Bacteroides thetaiotaomicron SusD (i.e alpha-helices and TPR regions). Based on this structural similarity, functional studies suggest that, RagB binding of glycans occurs at pockets on the molecular surface that are distinct from those of SusD.
TIGR04056, OMP_RagA_SusC, TonB-linked outer membrane protein, SusC/RagA family. This model describes a distinctive clade among the TonB-linked outer membrane proteins (OMP). Members of this family are restricted to the Bacteriodetes lineage (except for Gemmatimonas aurantiaca T-27 from the novel phylum Gemmatimonadetes) and occur in high copy numbers, with over 100 members from Bacteroides thetaiotaomicron VPI-5482 alone. Published descriptions of members of this family are available for RagA from Porphyromonas gingivalis, SusC from Bacteroides thetaiotaomicron, and OmpW from Bacteroides caccae. Members form pairs with members of the SusD/RagB family (pfam07980). Transporter complexes including these outer membrane proteins are likely to import large degradation products of proteins (e.g. RagA) or carbohydrates (e.g. SusC) as nutrients, rather than siderophores. [Transport and binding proteins, Unknown substrate].
pfam13585, CHU_C, C-terminal domain of CHU protein family. The function of this C-terminal domain is not known; there are several conserved tryptophan and asparagine residues.
cd03877, M28_like, M28 Zn-peptidase, many containing a protease-associated (PA) domain insert. Peptidase family M28 (also called aminopeptidase Y family), uncharacterized subfamily. The M28 family contains aminopeptidases as well as carboxypeptidases. They have co-catalytic zinc ions; each zinc ion is tetrahedrally co-ordinated, with three amino acid ligands plus activated water; one aspartate residue binds both metal ions. This subfamily is composed of uncharacterized proteins, many of which contain a protease-associated (PA) domain insert which may participate in substrate binding and/or promote conformational changes, influencing the stability and accessibility of the site to substrate. Some proteins in this subfamily are also associated with the PDZ domain, a widespread protein module that has been recruited to serve multiple functions during the course of evolution.
pfam12120, Arr-ms, Rifampin ADP-ribosyl transferase. This protein is found in bacteria. Proteins in this family are typically between 136 to 150 amino acids in length. The opportunistic pathogen Mycobacterium smegmatis is resistant to rifampin because of the presence of a chromosomally encoded rifampin ADP-ribosyltransferase (Arr-ms). Arr-ms is a small enzyme whose activity thus renders rifamycin antibiotics ineffective.
cd07130, ALDH_F7_AASADH, NAD+-dependent alpha-aminoadipic semialdehyde dehydrogenase, ALDH family members 7A1 and 7B. Alpha-aminoadipic semialdehyde dehydrogenase (AASADH, EC=1.2.1.31), also known as ALDH7A1, Antiquitin-1, ALDH7B, or delta-1-piperideine-6-carboxylate dehydrogenase (P6CDH), is a NAD+-dependent ALDH. Human ALDH7A1 is involved in the pipecolic acid pathway of lysine catabolism, catalyzing the oxidation of alpha-aminoadipic semialdehyde to alpha-aminoadipate. Arabidopsis thaliana ALDH7B4 appears to be an osmotic-stress-inducible ALDH gene encoding a turgor-responsive or stress-inducible ALDH. The Streptomyces clavuligerus P6CDH appears to be involved in cephamycin biosynthesis, catalyzing the second stage of the two-step conversion of lysine to alpha-aminoadipic acid. The ALDH7A1 enzyme and others in this group have been observed as tetramers, yet the bacterial P6CDH enzyme has been reported as a monomer.
TIGR00864, PCC, polycystin cation channel protein. The Polycystin Cation Channel (PCC) Family (TC 1.A.5) Polycystin is a huge protein of 4303aas. Its repeated leucine-rich (LRR) segment is found in many proteins. It contains 16 polycystic kidney disease (PKD) domains, one LDL-receptor class A domain, one C-type lectin family domain, and 16-18 putative TMSs in positions between residues 2200 and 4100. Polycystin-L has been shown to be a cation (Na+, K+ and Ca2+) channel that is activated by Ca2+. Two members of the PCC family (polycystin 1 and 2) are mutated in autosomal dominant polycystic kidney disease, and polycystin-L is deleted in mice with renal and retinal defects. Note: this model is restricted to the amino half.
pfam03193, RsgA_GTPase, RsgA GTPase. RsgA (also known as EngC and YjeQ) represents a protein family whose members are broadly conserved in bacteria and are indispensable for growth. The GTPase domain of RsgA is very similar to several P-loop GTPases, but differs in having a circular permutation of the GTPase structure described by a G4-G1-G3 pattern.
cd10434, GIY-YIG_UvrC_Cho, Catalytic GIY-YIG domain of nucleotide excision repair endonucleases UvrC, Cho, and similar proteins. UvrC is essential for nucleotide excision repair (NER). The N-terminal catalytic GIY-YIG domain of UvrC (also known as Uri domain) is responsible for the 3' incision reaction and the C-terminal half of UvrC, consisting of an UvrB-binding domain (UvrBb), EndoV-like nuclease domain and a helix-hairpin-helix (HhH) DNA-binding domain, contains the residues involved in 5' incision. The N- and C-terminal regions are joined by a common Cys-rich domain containing four conserved Cys residues. Besides UvrC, protein Cho (UvrC homolog) serves as a second endonuclease in E. coli NER. Cho contains GIY-YIG motif followed by a Cys-rich region and shares sequence homology with the N-terminal half of UvrC. It is capable of incising the DNA at the 3' side of a lesion in the presence of the UvrA and UvrB proteins during NER. The C-terminal half of Cho is a unique uncharacterized domain, which is distinct from that of UvrC. Moreover, unlike UvrC, Cho does not require the UvrC-binding domain of UvrB for the 3' incision reaction, which might cause the shift in incision position and the difference in incision efficiencies between Cho and UvrC on different damaged substrates. Due to this, the range of NER in E. coli can be broadened by combining action of Cho and UvrC. This family also includes many uncharacterized epsilon proofreading subunits of DNA polymerase III, which have an additional N-terminal ExoIII domain and a 3'-5' exonuclease domain homolog, fused to an UvrC-like region or a Cho-like region. The UvrC-like region includes a GIY-YIG motif, followed by a Cys-rich region, and an UvrB-binding domain (UvrBb), but lacks the EndoV-like nuclease domain and the helix-hairpin-helix (HhH) DNA-binding domain. The Cho-like region consists of a GIY-YIG motif, followed by the Cys-rich region, and the unique uncharacterized domain presenting in the C-terminal half of Cho. Some family members may not carry the Cys-rich region. This family also includes a specific Cho-like protein from G. violaceus, which possesses only UvrBb domain at the C-terminus, but lacks the additional N-terminal ExoIII domain. The oother two remote homologs of UvrC, Bacillus-I and -II, are included in this family as well. Both of them contain a GIY-YIG domain, but no Cys-rich region. Moreover, the whole C-terminal region of Bacillus-I is replaces by an unknown domain, and Bacillus-II possesses another unknown N-terminal extension.
pfam10099, RskA, Anti-sigma-K factor rskA. This domain, formerly known as DUF2337, is the anti-sigma-K factor, RskA. In Mycobacterium tuberculosis the protein positively regulates expression of the antigenic proteins MPB70 and MPB83.
pfam01641, SelR, SelR domain. Methionine sulfoxide reduction is an important process, by which cells regulate biological processes and cope with oxidative stress. MsrA, a protein involved in the reduction of methionine sulfoxides in proteins, has been known for four decades and has been extensively characterized with respect to structure and function. However, recent studies revealed that MsrA is only specific for methionine-S-sulfoxides. Because oxidized methionines occur in a mixture of R and S isomers in vivo, it was unclear how stereo-specific MsrA could be responsible for the reduction of all protein methionine sulfoxides. It appears that a second methionine sulfoxide reductase, SelR, evolved that is specific for methionine-R-sulfoxides, the activity that is different but complementary to that of MsrA. Thus, these proteins, working together, could reduce both stereoisomers of methionine sulfoxide. This domain is found both in SelR proteins and fused with the peptide methionine sulfoxide reductase enzymatic domain pfam01625. The domain has two conserved cysteine and histidines. The domain binds both selenium and zinc. The final cysteine is found to be replaced by the rare amino acid selenocysteine in some members of the family. This family has methionine-R-sulfoxide reductase activity.
The bacterium proteins that are colored denote the protein is present at specific phage-related keywords (such as 'capsid', 'head', 'integrase', 'plate', 'tail', 'fiber', 'coat', 'transposase', 'portal', 'terminase', 'protease' or 'lysin' and 'tRNA')
