TIGR02692, putative_tRNA_nucleotidyltransferase, tRNA adenylyltransferase. The enzyme tRNA adenylyltransferase, also called tRNA-nucleotidyltransferase and CCA-adding enzyme, can add or repair the required CCA triplet at the 3'-end of tRNA molecules. Genes encoding tRNA include the CCA tail in some but not all bacteria, and this enzyme may be required for viability. Members of this family represent a distinct clade within the larger family pfam01743 (tRNA nucleotidyltransferase/poly(A) polymerase family protein). The example from Streptomyces coelicolor was shown to act as a CCA-adding enzyme and not as a poly(A) polymerase. [Protein synthesis, tRNA and rRNA base modification].
pfam01797, Y1_Tnp, Transposase IS200 like. Transposases are needed for efficient transposition of the insertion sequence or transposon DNA. This family includes transposases for IS200 from E. coli.
TIGR03515, GldC, gliding motility-associated protein GldC. Members of this protein family are exclusive to the Bacteroidetes phylum (previously Cytophaga-Flavobacteria-Bacteroides). GldC is a protein linked to a type of rapid surface gliding motility found in certain Bacteroidetes, such as Flavobacterium johnsoniae and Cytophaga hutchinsonii. Knockouts of GldC do not abolish the gliding phenotype but do impair it. Gliding motility appears closely linked to chitin utilization in the model species Flavobacterium johnsoniae. Bacteroidetes with members of this protein family appear to have all of the genes associated with gliding motility.
pfam05559, DUF763, Protein of unknown function (DUF763). This family consists of several uncharacterized bacterial and archaeal proteins of unknown function.
cd00553, NAD_synthase, NAD+ synthase is a homodimer, which catalyzes the final step in de novo nicotinamide adenine dinucleotide (NAD+) biosynthesis, an amide transfer from either ammonia or glutamine to nicotinic acid adenine dinucleotide (NaAD). The conversion of NaAD to NAD+ occurs via an NAD-adenylate intermediate and requires ATP and Mg2+. The intemediate is subsequently cleaved into NAD+ and AMP. In many prokaryotes, such as E. coli , NAD synthetase consists of a single domain and is strictly ammonia dependent. In contrast, eukaryotes and other prokaryotes have an additional N-terminal amidohydrolase domain that prefer glutamine, Interestingly, NAD+ synthases in these prokaryotes, can also utilize ammonia as an amide source .
pfam01053, Cys_Met_Meta_PP, Cys/Met metabolism PLP-dependent enzyme. This family includes enzymes involved in cysteine and methionine metabolism. The following are members: Cystathionine gamma-lyase, Cystathionine gamma-synthase, Cystathionine beta-lyase, Methionine gamma-lyase, OAH/OAS sulfhydrylase, O-succinylhomoserine sulfhydrylase All of these members participate is slightly different reactions. All these enzymes use PLP (pyridoxal-5'-phosphate) as a cofactor.
pfam09905, VF530, DNA-binding protein VF530. VF530 contains a unique four-helix motif that shows some similarity to the C-terminal double-stranded DNA (dsDNA) binding domain of RecA, as well as other nucleic acid binding domains.
cd08897, SRPBCC_CalC_Aha1-like_4, Putative hydrophobic ligand-binding SRPBCC domain of an uncharacterized subgroup of CalC- and Aha1-like proteins. SRPBCC (START/RHO_alpha_C/PITP/Bet_v1/CoxG/CalC) domain of a functionally uncharacterized subgroup of CalC- and Aha1-like proteins. This group shows similarity to the SRPBCC domains of Micromonospora echinospora CalC (a protein which confers resistance to enediynes) and human Aha1 (one of several co-chaperones which regulate the dimeric chaperone Hsp90), and belongs to the SRPBCC domain superfamily of proteins that bind hydrophobic ligands. SRPBCC domains have a deep hydrophobic ligand-binding pocket and they bind diverse ligands.
cd06588, PhnB_like, Escherichia coli PhnB and similar proteins. The Escherichia coli phnB gene is found next to an operon of fourteen genes (phnC-to-phnP) related to the cleavage of carbon-phosphorus (C-P) bonds in unactivated alkylphosphonates, supporting bacterial growth on alkylphosphonates as the sole phosphorus source. It was originally considered part of that operon. PhnB appears to play no direct catalytic role in the usage of alkylphosphonate. Although many of the proteins in this family have been annotated as 3-demethylubiquinone-9 3-methyltransferase enzymes by automatic annotation programs, the experimental evidence for this assignment is lacking. In Escherichia coli, the gene coding 3-demethylubiquinone-9 3-methyltransferase enzyme is ubiG, which belongs to the AdoMet-MTase protein family. PhnB-like proteins adopt a structural fold similar to bleomycin resistance proteins, glyoxalase I, and type I extradiol dioxygenases.
pfam12867, DinB_2, DinB superfamily. The DinB family are an uncharacterized family of potential enzymes. The structure of these proteins is composed of a four helix bundle.
cd16016, AP-SPAP, SPAP is a subclass of alkaline phosphatase (AP). Alkaline phosphatases are non-specific phosphomonoesterases that catalyze the hydrolysis reaction via a phosphoseryl intermediate to produce inorganic phosphate and the corresponding alcohol, optimally at high pH. Alkaline phosphatase exists as a dimer, each monomer binding 2 zinc atoms and one magnesium atom, which are essential for enzymatic activity. Although SPAP is a subclass of alkaline phosphatase, SPAP has many differences from other APs: 1) the catalytic residue is a threonine instead of serine, 2) there is no binding pocket for the third metal ion, and 3) the arginine residue forming bidentate hydrogen bonding is deleted in SPAP. A lysine and an asparagine residue, recruited together for the first time into the active site, bind the substrate phosphoryl group in a manner not observed before in any other AP.
pfam01300, Sua5_yciO_yrdC, Telomere recombination. This domain has been shown to bind preferentially to dsRNA. The domain is found in SUA5 as well as HypF and YrdC. It has also been shown to be required for telomere recombniation in yeast.
cd05142, Barstar, Barstar is an intracellular inhibitor of barnase, an extracellular ribonuclease of Bacillus amyloliquefaciens. Barstar binds tightly to the barnase active site and sterically blocks it thus inhibiting its potentially lethal RNase activity inside the cell. Barstar also binds and inhibits a ribonuclease called RNase Sa (produced by Streptomyces aureofaciens) which belongs to the same enzyme family as does barnase.
cd00933, barnase, Barnase, a member of the family of homologous microbial ribonucleases, catalyses the cleavage of single-stranded RNA via a two-step mechanism thought to be similar to that of pancreatic ribonuclease. The mechanism involves a transesterification to give a 2', 3'-cyclic phosphate intermediate, followed by hydrolysis to yield a 3' nucleotide. The active site residues His and Glu act as general acid-base groups during catalysis, while the Arg and Lys residues are important in binding the reactive phosphate, the latter probably binding the phosphate in the transition state. Barstar, a small 89 residue intracellular protein is a natural inhibitor of Barnase.
cd10449, GIY-YIG_SLX1_like, Catalytic GIY-YIG domain of yeast structure-specific endonuclease subunit SLX1 and its homologs. Structure-specific endonuclease subunit SLX1 is a highly conserved protein from yeast to human, with an N-terminal GIY-YIG endonuclease domain and a C-terminal PHD-type zinc finger postulated to mediate protein-protein or protein-DNA interaction. SLX1 forms active heterodimeric complexes with its SLX4 partner, which has additional roles in the DNA damage response that are distinct from the function of the heterodimeric SLX1-SLX4 nuclease. In yeast, the SLX1-SLX4 complex functions as a 5' flap endonuclease that maintains ribosomal DNA copy number, where SLX1 and SLX4 are shown to be catalytic and regulatory subunits, respectively. This endonuclease introduces single-strand cuts in duplex DNA on the 3' side of junctions with single-strand DNA. In addition to 5' flap endonuclease activity, human SLX1-SLX4 complex has been identified as a Holliday junction resolvase that promotes symmetrical cleavage of static and migrating Holliday junctions. SLX1 also associates with MUS81, EME1, C20orf94, PLK1, and ERCC1. Some eukaryotic SLX1 homologs lack the zinc finger domain, but possess intrinsically unstructured extensions of unknown function. These unstructured segments might be involved in interactions with other proteins.
cd10449, GIY-YIG_SLX1_like, Catalytic GIY-YIG domain of yeast structure-specific endonuclease subunit SLX1 and its homologs. Structure-specific endonuclease subunit SLX1 is a highly conserved protein from yeast to human, with an N-terminal GIY-YIG endonuclease domain and a C-terminal PHD-type zinc finger postulated to mediate protein-protein or protein-DNA interaction. SLX1 forms active heterodimeric complexes with its SLX4 partner, which has additional roles in the DNA damage response that are distinct from the function of the heterodimeric SLX1-SLX4 nuclease. In yeast, the SLX1-SLX4 complex functions as a 5' flap endonuclease that maintains ribosomal DNA copy number, where SLX1 and SLX4 are shown to be catalytic and regulatory subunits, respectively. This endonuclease introduces single-strand cuts in duplex DNA on the 3' side of junctions with single-strand DNA. In addition to 5' flap endonuclease activity, human SLX1-SLX4 complex has been identified as a Holliday junction resolvase that promotes symmetrical cleavage of static and migrating Holliday junctions. SLX1 also associates with MUS81, EME1, C20orf94, PLK1, and ERCC1. Some eukaryotic SLX1 homologs lack the zinc finger domain, but possess intrinsically unstructured extensions of unknown function. These unstructured segments might be involved in interactions with other proteins.
TIGR01068, Thioredoxin-like_protein_slr0233, thioredoxin. Several proteins, such as protein disulfide isomerase, have two or more copies of a domain closely related to thioredoxin. This model is designed to recognize authentic thioredoxin, a small protein that should be hit exactly once by this model. Any protein that hits once with a score greater than the second (per domain) trusted cutoff may be taken as thioredoxin. [Energy metabolism, Electron transport].
pfam04357, TamB, TamB, inner membrane protein subunit of TAM complex. TamB is an integral inner membrane protein that forms a complex - the translocation and assembly module or TAM - with the outer membrane protein, TamA. TAM is responsible for the efficient secretion of the adhesin protein Ag43 in E.coli K-12.
pfam08889, WbqC, WbqC-like protein family. This family of proteins are functionally uncharacterized. However it is found in an O-antigen gene cluster in E. coli and other bacteria suggesting a role in O-antigen production. Feng et al. suggest that wbnG may code for a glycine transferase.
TIGR01490, Uncharacterized_protein_Rv3661/MT3761, HAD-superfamily subfamily IB hydrolase, TIGR01490. This hypothetical equivalog is a member of the IB subfamily (TIGR01488) of the haloacid dehalogenase (HAD) superfamily of aspartate-nucleophile hydrolases. The sequences modelled here are all bacterial. The IB subfamily includes the enzyme phosphoserine phosphatase (TIGR00338). Due to this relationship, several of these sequences have been annotated as "phosphoserine phosphatase related proteins," or "Phosphoserine phosphatase-family enzymes." There is presently no evidence that any of the enzymes in this model possess PSPase activity. OMNI|NTL01ML1250 is annotated as a "possible transferase," however this is due to the C-terminal domain found on this sequence which is homologous to a group of glycerol-phosphate acyltransferases (between trusted and noise to TIGR00530). A subset of these sequences including OMNI|CC1962, the Caulobacter crescentus CicA protein cluster together and may represent a separate equivalog. [Unknown function, Enzymes of unknown specificity].
cd13963, PT_UbiA_2, UbiA family of prenyltransferases (PTases), Unknown subgroup. Many characterized members of the UbiA prenyltransferase family are aromatic prenyltransferases and play an important role in the biosynthesis of heme, chlorophyll, vitamin E, and vitamin K. They contain two copies of a motif similar to the active site DxxD motif of trans-prenyltransferases and are potentially related. Prenyltransferases (PTs) catalyze the regioselective transfer of prenyl moieties onto a wide variety of substrates and play an important role in many biosynthetic pathways. The function of this subgroup is unknown.
cd07483, Peptidases_S8_Subtilisin_Novo-like, Peptidase S8 family domain in Subtilisin_Novo-like proteins. Subtilisins are a group of alkaline proteinases originating from different strains of Bacillus subtilis. Novo is one of the strains that produced enzymes belonging to this group. The enzymes obtained from the Novo and BPN' strains are identical. The Carlsburg and Novo subtilisins are thought to have arisen from a common ancestral protein. They have similar peptidase and esterase activities, pH profiles, catalyze transesterification reactions, and are both inhibited by diispropyl fluorophosphate, though they differ in 85 positions in the amino acid sequence. Members of the peptidases S8 and S35 clan include endopeptidases, exopeptidases and also a tripeptidyl-peptidase. The S8 family has an Asp/His/Ser catalytic triad similar to that found in trypsin-like proteases, but do not share their three-dimensional structure and are not homologous to trypsin. The S53 family contains a catalytic triad Glu/Asp/Ser with an additional acidic residue Asp in the oxyanion hole, similar to that of subtilisin.. The stability of these enzymes may be enhanced by calcium, some members have been shown to bind up to 4 ions via binding sites with different affinity. Some members of this clan contain disulfide bonds. These enzymes can be intra- and extracellular, some function at extreme temperatures and pH values.
cd10449, GIY-YIG_SLX1_like, Catalytic GIY-YIG domain of yeast structure-specific endonuclease subunit SLX1 and its homologs. Structure-specific endonuclease subunit SLX1 is a highly conserved protein from yeast to human, with an N-terminal GIY-YIG endonuclease domain and a C-terminal PHD-type zinc finger postulated to mediate protein-protein or protein-DNA interaction. SLX1 forms active heterodimeric complexes with its SLX4 partner, which has additional roles in the DNA damage response that are distinct from the function of the heterodimeric SLX1-SLX4 nuclease. In yeast, the SLX1-SLX4 complex functions as a 5' flap endonuclease that maintains ribosomal DNA copy number, where SLX1 and SLX4 are shown to be catalytic and regulatory subunits, respectively. This endonuclease introduces single-strand cuts in duplex DNA on the 3' side of junctions with single-strand DNA. In addition to 5' flap endonuclease activity, human SLX1-SLX4 complex has been identified as a Holliday junction resolvase that promotes symmetrical cleavage of static and migrating Holliday junctions. SLX1 also associates with MUS81, EME1, C20orf94, PLK1, and ERCC1. Some eukaryotic SLX1 homologs lack the zinc finger domain, but possess intrinsically unstructured extensions of unknown function. These unstructured segments might be involved in interactions with other proteins.
cd10449, GIY-YIG_SLX1_like, Catalytic GIY-YIG domain of yeast structure-specific endonuclease subunit SLX1 and its homologs. Structure-specific endonuclease subunit SLX1 is a highly conserved protein from yeast to human, with an N-terminal GIY-YIG endonuclease domain and a C-terminal PHD-type zinc finger postulated to mediate protein-protein or protein-DNA interaction. SLX1 forms active heterodimeric complexes with its SLX4 partner, which has additional roles in the DNA damage response that are distinct from the function of the heterodimeric SLX1-SLX4 nuclease. In yeast, the SLX1-SLX4 complex functions as a 5' flap endonuclease that maintains ribosomal DNA copy number, where SLX1 and SLX4 are shown to be catalytic and regulatory subunits, respectively. This endonuclease introduces single-strand cuts in duplex DNA on the 3' side of junctions with single-strand DNA. In addition to 5' flap endonuclease activity, human SLX1-SLX4 complex has been identified as a Holliday junction resolvase that promotes symmetrical cleavage of static and migrating Holliday junctions. SLX1 also associates with MUS81, EME1, C20orf94, PLK1, and ERCC1. Some eukaryotic SLX1 homologs lack the zinc finger domain, but possess intrinsically unstructured extensions of unknown function. These unstructured segments might be involved in interactions with other proteins.
