TIGR04122, hypothetical_protein, putative exonuclease, DNA ligase-associated. Members of this protein family frequently are found annotated as a putative exonuclease involved in mRNA processing. This protein is found, exclusively in bacteria, associated with three other proteins: an ATP-dependent DNA ligase, a helicase, and putative phosphoesterase.
TIGR03434, ADOP, Acidobacterial duplicated orphan permease. Members of this protein family are found, so far, only in three species of Acidobacteria, namely Acidobacteria bacterium Ellin345, Acidobacterium capsulatum ATCC 51196, and Solibacter usitatus Ellin6076, where they form large paralogous families. Each protein contains two copies of a domain called the efflux ABC transporter permease protein (pfam02687). However, unlike other members of that family (including LolC, FtsX, and MacB), genes for these proteins are essentially never found fused or adjacent to ABC transporter ATP-binding protein (pfam00005) genes. We name this family ADOP, for Acidobacterial Duplicated Orphan Permease, to reflect the restricted lineage, internal duplication, lack of associated ATP-binding cassette proteins, and permease homology. The function is unknown.
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.
cd08977, SusD, starch binding outer membrane protein SusD. SusD-like proteins from Bacteroidetes, members of the human distal gut microbiota, are part of the starch utilization system (Sus). Sus is one of the large clusters of glycosyl hydrolases, called polysaccharide utilization loci (PULs), which play an important role in polysaccharide recognition and uptake, and it is needed for growth on amylose, amylopectin, pullulan, and maltooligosaccharides. SusD, together with SusC, a predicted beta-barrel porin, forms the minimum outer-membrane starch-binding complex. The adult human distal gut microbiota is essential for digestion of a large variety of dietary polysaccharides, for which humans lack the necessary glycosyl hydrolases.
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].
cd05387, BY-kinase, bacterial tyrosine-kinase. Bacterial tyrosine (BY)-kinases catalyze the autophosphorylation on a C-terminal tyrosine cluster and also phosphorylate endogenous protein substrates by using ATP as phosphoryl donor. Besides their capacity to function as tyrosine kinase, most of these proteins are also involved in the production and transport of exopolysaccharides. BY-kinases are involved in a number of physiological processes ranging from stress resistance to pathogenicity.
cd07366, 3MGA_Dioxygenase, Subunit B of the Class III Extradiol ring-cleavage dioxygenase, 3-O-Methylgallate Dioxygenase, which catalyzes the oxidization and subsequent ring-opening of 3-O-Methylgallate. 3-O-Methylgallate Dioxygenase catalyzes the oxidization and subsequent ring-opening of 3-O-Methylgallate (3MGA) between carbons 2 and 3. 3-O-Methylgallate Dioxygenase is a key enzyme in the syringate degradation pathway, in which the syringate is first converted to 3-O-Methylgallate by O-demethylase. This enzyme is a member of the class III extradiol dioxygenase family, a group of enzymes which uses a non-heme Fe(II) to cleave aromatic rings between a hydroxylated carbon and an adjacent non-hydroxylated carbon. LigAB-like enzymes are usually composed of two subunits, designated A and B, which form a tetramer composed of two copies of each subunit. This model represents the catalytic subunit, B.
cd18617, GH43_XynB-like, Glycosyl hydrolase family 43, such as Bacteroides ovatus alpha-L-arabinofuranosidase (BoGH43, XynB). This glycosyl hydrolase family 43 (GH43) subgroup includes enzymes that have been characterized to have alpha-L-arabinofuranosidase (EC 3.2.1.55) and beta-1,4-xylosidase (beta-D-xylosidase;xylan 1,4-beta-xylosidase; EC 3.2.1.37) activities. Beta-1,4-xylosidases are part of an array of hemicellulases that are involved in the final breakdown of plant cell-wall whereby they degrade xylan. They hydrolyze beta-1,4 glycosidic bonds between two xylose units in short xylooligosaccharides. These are inverting enzymes (i.e. they invert the stereochemistry of the anomeric carbon atom of the substrate) that have an aspartate as the catalytic general base, a glutamate as the catalytic general acid and another aspartate that is responsible for pKa modulation and orienting the catalytic acid. Also included in this subfamily are Bacteroides ovatus alpha-L-arabinofuranosidases, BoGH43A and BoGH43B, both having a two-domain architecture, consisting of an N-terminal 5-bladed beta-propeller domain harboring the catalytic active site, and a C-terminal beta-sandwich domain. However, despite significant functional overlap between these two enzymes, BoGH43A and BoGH43B share just 41% sequence identity. The latter appears to be significantly less active on the same substrates, suggesting that these paralogs may play subtly different roles during the degradation of xyloglucans from different sources, or may function most optimally at different stages in the catabolism of xyloglucan oligosaccharides (XyGOs), for example before or after hydrolysis of certain side-chain moieties. It also includes Phanerochaete chrysosporium BKM-F-1767 Xyl, a bifunctional xylosidase/arabinofuranosidase. A common structural feature of GH43 enzymes is a 5-bladed beta-propeller domain that contains the catalytic acid and catalytic base. A long V-shaped groove, partially enclosed at one end, forms a single extended substrate-binding surface across the face of the propeller.
cd09019, galactose_mutarotase_like, galactose mutarotase_like. Galactose mutarotase catalyzes the conversion of beta-D-galactose to alpha-D-galactose. Beta-D-galactose is produced by the degradation of lactose, a disaccharide composed of beta-D-glucose and beta-D-galactose. This epimerization reaction is the first step in the four-step Leloir pathway, which converts galactose into metabolically important glucose. This epimerization step is followed by the phosophorylation of alpha-D-galactose by galactokinase, an enzyme which can only act on the alpha anomer. A glutamate and a histidine residue of the galactose mutarotase have been shown to be critical for catalysis, the glutamate serves as the active site base to initiate the reaction by removing the proton from the C-1 hydroxyl group of the sugar substrate, and the histidine as the active site acid to protonate the C-5 ring oxygen. Galactose mutarotase is a member of the aldose-1-epimerase superfamily.
pfam07715, Plug, TonB-dependent Receptor Plug Domain. The Plug domain has been shown to be an independently folding subunit of the TonB-dependent receptors. It acts as the channel gate, blocking the pore until the channel is bound by ligand. At this point it under goes conformational changes opens the channel.
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.
cd02850, E_set_Cellulase_N, N-terminal Early set domain associated with the catalytic domain of cellulase. E or "early" set domains are associated with the catalytic domain of cellulases at the N-terminal end. Cellulases are O-glycosyl hydrolases (GHs) that hydrolyze beta 1-4 glucosidic bonds in cellulose. They are usually categorized into either exoglucanases, which sequentially release terminal sugar units from the cellulose chain, or endoglucanases, which also attack the chain internally. The N-terminal domain of cellulase may be related to the immunoglobulin and/or fibronectin type III superfamilies. These domains are associated with different types of catalytic domains at either the N-terminal or C-terminal end and may be involved in homodimeric/tetrameric/dodecameric interactions. Members of this family include members of the alpha amylase family, sialidase, galactose oxidase, cellulase, cellulose, hyaluronate lyase, chitobiase, and chitinase, among others.
cd01820, PAF_acetylesterase_like, PAF_acetylhydrolase (PAF-AH)_like subfamily of SGNH-hydrolases. Platelet-activating factor (PAF) and PAF-AH are key players in inflammation and in atherosclerosis. PAF-AH is a calcium independent phospholipase A2 which exhibits strong substrate specificity towards PAF, hydrolyzing an acetyl ester at the sn-2 position. PAF-AH also degrades a family of oxidized PAF-like phospholipids with short sn-2 residues. In addition, PAF and PAF-AH are associated with neural migration and mammalian reproduction.
pfam15979, Glyco_hydro_115, Glycosyl hydrolase family 115. Glyco_hydro_115 is a family of glycoside hydrolases likely to have the activity of xylan a-1,2-glucuronidase, EC:3.2.1.131, or a-(4-O-methyl)-glucuronidase EC:3.2.1.-.
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].
pfam03629, SASA, Carbohydrate esterase, sialic acid-specific acetylesterase. The catalytic triad of this esterase enzyme comprises residues Ser127, His403 and Asp391 in UniProtKB:P70665.
pfam07944, Glyco_hydro_127, Beta-L-arabinofuranosidase, GH127. One member of this family, from Bidobacterium longicum, UniProtKB:E8MGH8, has been characterized as an unusual beta-L-arabinofuranosidase enzyme, EC:3.2.1.185. It rleases l-arabinose from the l-arabinofuranose (Araf)-beta1,2-Araf disaccharide and also transglycosylates 1-alkanols with retention of the anomeric configuration. Terminal beta-l-arabinofuranosyl residues have been found in arabinogalactan proteins from a mumber of different plantt species. beta-l-Arabinofuranosyl linkages with 1-4 arabinofuranosides are also found in the sugar chains of extensin and solanaceous lectins, hydroxyproline (Hyp)2-rich glycoproteins that are widely observed in plant cell wall fractions. The critical residue for catalytic activity is Glu-338, in a ET/SCAS sequence context.
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.
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')