cd03268, ABC_BcrA_bacitracin_resist, ATP-binding cassette domain of the bacitracin-resistance transporter. The BcrA subfamily represents ABC transporters involved in peptide antibiotic resistance. Bacitracin is a dodecapeptide antibiotic produced by B. licheniformis and B. subtilis. The synthesis of bacitracin is non-ribosomally catalyzed by a multi-enzyme complex BcrABC. Bacitracin has potent antibiotic activity against gram-positive bacteria. The inhibition of peptidoglycan biosynthesis is the best characterized bacterial effect of bacitracin. The bacitracin resistance of B. licheniformis is mediated by the ABC transporter Bcr which is composed of two identical BcrA ATP-binding subunits and one each of the integral membrane proteins, BcrB and BcrC. B. subtilis cells carrying bcr genes on high-copy number plasmids develop collateral detergent sensitivity, a similar phenomenon in human cells with overexpressed multi-drug resistance P-glycoprotein.
pfam13399, LytR_C, LytR cell envelope-related transcriptional attenuator. This family appears at the C-terminus of members of the LytR_cpsA_psr, pfam03816, family.
pfam16918, PknG_TPR, Protein kinase G tetratricopeptide repeat. This domain is found at the C-terminus of protein kinase G and contains a tetratricopeptide repeat (TPR).
cd13690, PBP2_GluB, Substrate binding domain of ABC glutamate transporter; the type 2 periplasmic binding protein fold. This group includes periplasmic glutamate-binding domain GluB from Corynebacterium efficiens and its related proteins. The GluB domain belongs to the type 2 periplasmic binding protein fold superfamily (PBP2), whose many members are involved in chemotaxis and uptake of nutrients and other small molecules from the extracellular space as a primary receptor. The PBP2 proteins are typically comprised of two globular subdomains connected by a flexible hinge and bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap. After binding their specific ligand with high affinity, they can interact with a cognate membrane transport complex comprised of two integral membrane domains and two receptor cytoplasmically-located ATPase domains. This interaction triggers the ligand translocation across the cytoplasmic membrane energized by ATP hydrolysis.
cd09086, ExoIII-like_AP-endo, Escherichia coli exonuclease III (ExoIII) and Neisseria meningitides NExo-like subfamily of the ExoIII family purinic/apyrimidinic (AP) endonucleases. This subfamily includes Escherichia coli ExoIII, Neisseria meningitides NExo,and related proteins. These are ExoIII family AP endonucleases and they belong to the large EEP (exonuclease/endonuclease/phosphatase) superfamily that contains functionally diverse enzymes that share a common catalytic mechanism of cleaving phosphodiester bonds. AP endonucleases participate in the DNA base excision repair (BER) pathway. AP sites are one of the most common lesions in cellular DNA. During BER, the damaged DNA is first recognized by DNA glycosylase. AP endonucleases then catalyze the hydrolytic cleavage of the phosphodiester bond 5' to the AP site, and this is followed by the coordinated actions of DNA polymerase, deoxyribose phosphatase, and DNA ligase. If left unrepaired, AP sites block DNA replication, and have both mutagenic and cytotoxic effects. AP endonucleases can carry out a variety of excision and incision reactions on DNA, including 3'-5' exonuclease, 3'-deoxyribose phosphodiesterase, 3'-phosphatase, and occasionally, nonspecific DNase activities. Different AP endonuclease enzymes catalyze the different reactions with different efficiencies. Many organisms have two AP endonucleases, usually one is the dominant AP endonuclease, the other has weak AP endonuclease activity. For example, Neisseria meningitides Nape and NExo, and exonuclease III (ExoIII) and endonuclease IV (EndoIV) in Escherichia coli. NExo and ExoIII are found in this subfamily. NExo is the non-dominant AP endonuclease. It exhibits strong 3'-5' exonuclease and 3'-deoxyribose phosphodiesterase activities. Escherichia coli ExoIII is an active AP endonuclease, and in addition, it exhibits double strand (ds)-specific 3'-5' exonuclease, exonucleolytic RNase H, 3'-phosphomonoesterase and 3'-phosphodiesterase activities, all catalyzed by a single active site. Class II AP endonucleases have been classified into two families, designated ExoIII and EndoIV, based on their homology to the Escherichia coli enzymes ExoIII and endonuclease IV (EndoIV). This subfamily belongs to the ExoIII family; the EndoIV family belongs to a different superfamily.
cd02883, Nudix_Hydrolase, Nudix hydrolase is a superfamily of enzymes found in all three kingdoms of life, and it catalyzes the hydrolysis of NUcleoside DIphosphates linked to other moieties, X. Enzymes belonging to this superfamily require a divalent cation, such as Mg2+ or Mn2+ for their activity. Members of this family are recognized by a highly conserved 23-residue nudix motif (GX5EX7REUXEEXGU, where U = I, L or V), which forms a structural motif that functions as a metal binding and catalytic site. Substrates of nudix hydrolase include intact and oxidatively damaged nucleoside triphosphates, dinucleoside polyphosphates, nucleotide-sugars and dinucleotide enzymes. These substrates are metabolites or cell signaling molecules that require regulation during different stages of the cell cycle or during periods of stress. In general, the role of the nudix hydrolase is to sanitize the nucleotide pools and to maintain cell viability, thereby serving as surveillance and "house-cleaning" enzymes. Substrate specificity is used to define child families within the superfamily. Differences in substrate specificity are determined by the N-terminal extension or by residues in variable loop regions. Mechanistically, substrate hydrolysis occurs by a nucleophilic substitution reaction, with variation in the numbers and roles of divalent cations required. This superfamily consists of at least nine families: IPP (isopentenyl diphosphate) isomerase, ADP ribose pyrophosphatase, mutT pyrophosphohydrolase, coenzyme-A pyrophosphatase, MTH1-7,8-dihydro-8-oxoguanine-triphosphatase, diadenosine tetraphosphate hydrolase, NADH pyrophosphatase, GDP-mannose hydrolase and the c-terminal portion of the mutY adenine glycosylase.
cd17320, MFS_MdfA_MDR_like, Multidrug transporter MdfA and similar multidrug resistance (MDR) transporters of the Major Facilitator Superfamily. This family is composed of bacterial multidrug resistance (MDR) transporters including several proteins from Escherichia coli such as MdfA (also called chloramphenicol resistance pump Cmr), EmrD, MdtM, MdtL, bicyclomycin resistance protein (also called sulfonamide resistance protein), and the uncharacterized inner membrane transport protein YdhC. EmrD is a proton-dependent secondary transporter, first identified as an efflux pump for uncouplers of oxidative phosphorylation. It expels a range of drug molecules and amphipathic compounds across the inner membrane of E. coli. Similarly, MdfA is a secondary multidrug transporter that exports a broad spectrum of structurally and electrically dissimilar toxic compounds. These MDR transporters are drug/H+ antiporters (DHA) belonging to the Major Facilitator Superfamily (MFS) of membrane transport proteins, which are thought to function through a single substrate binding site, alternating-access mechanism involving a rocker-switch type of movement.
pfam00583, Acetyltransf_1, Acetyltransferase (GNAT) family. This family contains proteins with N-acetyltransferase functions such as Elp3-related proteins.
cd02612, HAD_PGPPase, phosphatidylglycerol-phosphate phosphatase, similar to Escherichia coli K-12 phosphatidylglycerol-phosphate phosphatase C. This family includes Escherichia coli K-12 phosphatidylglycerol-phosphate phosphatase C, PgpC (previously named yfhB) which catalyzes the dephosphorylation of phosphatidylglycerol-phosphate (PGP) to phosphatidylglycerol (PG). This family belongs to the haloacid dehalogenase-like (HAD) hydrolases, a large superfamily of diverse enzymes that catalyze carbon or phosphoryl group transfer reactions on a range of substrates, using an active site aspartate in nucleophilic catalysis. Members of this superfamily include 2-L-haloalkanoic acid dehalogenase, azetidine hydrolase, phosphonoacetaldehyde hydrolase, phosphoserine phosphatase, phosphomannomutase, P-type ATPases and many others. HAD hydrolases are found in all three kingdoms of life, and most genomes are predicted to contain multiple HAD-like proteins. Members possess a highly conserved alpha/beta core domain, and many also possess a small cap domain, the fold and function of which is variable. HAD hydrolases are sometimes referred to as belonging to the DDDD superfamily of phosphohydrolases.
cd01151, GCD, Glutaryl-CoA dehydrogenase. Glutaryl-CoA dehydrogenase (GCD). GCD is an acyl-CoA dehydrogenase, which catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and carbon dioxide in the catabolism of lysine, hydroxylysine, and tryptophan. It uses electron transfer flavoprotein (ETF) as an electron acceptor. GCD is a homotetramer. GCD deficiency leads to a severe neurological disorder in humans.
cd03426, CoAse, Coenzyme A pyrophosphatase (CoAse), a member of the Nudix hydrolase superfamily, functions to catalyze the elimination of oxidized inactive CoA, which can inhibit CoA-utilizing enzymes. The need of CoAses mainly arises under conditions of oxidative stress. CoAse has a conserved Nudix fold and requires a single divalent cation for catalysis. In addition to a signature Nudix motif G[X5]E[X7]REUXEEXGU, where U is Ile, Leu, or Val, CoAse contains an additional motif upstream called the NuCoA motif (LLTXT(SA)X3RX3GX3FPGG) which is postulated to be involved in CoA recognition. CoA plays a central role in lipid metabolism. It is involved in the initial steps of fatty acid sythesis in the cytosol, in the oxidation of fatty acids and the citric acid cycle in the mitochondria, and in the oxidation of long-chain fatty acids in peroxisomes. CoA has the important role of activating fatty acids for further modification into key biological signalling molecules.
cd16278, metallo-hydrolase-like_MBL-fold, uncharacterized subgroup of the MBL-fold_metallo-hydrolase superfamily; MBL-fold metallo hydrolase domain. Members of the MBL-fold metallohydrolase superfamily are mainly hydrolytic enzymes which carry out a variety of biological functions. The class B metal beta-lactamases (MBLs) for which this fold was named perform only a small fraction of the activities included in this superfamily.Activities carried out by superfamily members include class B beta-lactamases, hydroxyacylglutathione hydrolases, AHL (acyl homoserine lactone) lactonases, persulfide dioxygenases, flavodiiron proteins, cleavage and polyadenylation specificity factors such as the Int9 and Int11 subunits of Integrator, Sdsa1-like and AtsA-like arylsulfatases, 5'-exonucleases human SNM1A and yeast Pso2p, ribonuclease J and ribonuclease Z, cyclic nucleotide phosphodiesterases, insecticide hydrolases, and proteins required for natural transformation competence. Classical members of the superfamily are di-, or less commonly mono-, zinc-ion-dependent hydrolases, however the diversity of biological roles is reflected in variations in the active site metallo-chemistry.
cd02966, TlpA_like_family, TlpA-like family; composed of TlpA, ResA, DsbE and similar proteins. TlpA, ResA and DsbE are bacterial protein disulfide reductases with important roles in cytochrome maturation. They are membrane-anchored proteins with a soluble TRX domain containing a CXXC motif located in the periplasm. The TRX domains of this family contain an insert, approximately 25 residues in length, which correspond to an extra alpha helix and a beta strand when compared with TRX. TlpA catalyzes an essential reaction in the biogenesis of cytochrome aa3, while ResA and DsbE are essential proteins in cytochrome c maturation. Also included in this family are proteins containing a TlpA-like TRX domain with domain architectures similar to E. coli DipZ protein, and the N-terminal TRX domain of PilB protein from Neisseria which acts as a disulfide reductase that can recylce methionine sulfoxide reductases.
pfam07332, Phage_holin_3_6, Putative Actinobacterial Holin-X, holin superfamily III. Phage_holin_3_6 is a family of small hydrophobic proteins with two or three transmembrane domains of the Hol-X family. Holin proteins are produced by double-stranded DNA bacteriophages that use an endolysin-holin strategy to achieve lysis of their hosts. The endolysins are peptidoglycan-degrading enzymes that are usually accumulated in the cytosol until access to the cell wall substrate is provided by the holin membrane lesion.
TIGR03815, CpaE_hom_Actino, helicase/secretion neighborhood CpaE-like protein. Members of this protein family belong to the MinD/ParA family of P-loop NTPases, and in particular show homology to the CpaE family of pilus assembly proteins (see ). Nearly all members are found, not only in a gene context consistent with pilus biogenesis or a pilus-like secretion apparatus, but also near a DEAD/DEAH-box helicase, suggesting an involvement in DNA transfer activity. The model describes a clade restricted to the Actinobacteria.
pfam14029, DUF4244, Protein of unknown function (DUF4244). This family of proteins is functionally uncharacterized. This family of proteins is found in bacteria. Proteins in this family are typically between 66 and 95 amino acids in length. There is a conserved EYA sequence motif.
TIGR03816, tadE_like_DECH, helicase/secretion neighborhood TadE-like protein. Members of this small, highly hydrophobic protein family occur in a pilus/secretion-like region that usually is next to an uncharacterized DEAH-box helicase, in Actinobacteria. Members show sequence similarity to the TadE-like family described by pfam07811. The function is unknown. [Unknown function, General].
TIGR03819, heli_sec_ATPase, helicase/secretion neighborhood ATPase. Members of this protein family comprise a distinct clade of putative ATPase associated with an integral membrane complex likely to act in pilus formation, secretion, or conjugal transfer. The association of most members with a nearby gene for a DEAH-box helicase suggests a role in conjugal transfer.
pfam02674, Colicin_V, Colicin V production protein. Colicin V production protein is required in E. Coli for colicin V production from plasmid pColV-K30. This protein is coded for in the purF operon.
cd03450, NodN, NodN (nodulation factor N) contains a single hot dog fold similar to those of the peroxisomal Hydratase-Dehydrogenase-Epimerase (HDE) protein, and the fatty acid synthase beta subunit. Rhizobium and related species form nodules on the roots of their legume hosts, a symbiotic process that requires production of Nod factors, which are signal molecules involved in root hair deformation and meristematic cell division. The nodulation gene products, including NodN, are involved in producing the Nod factors, however the role played by NodN is unclear.
TIGR04448, creatininase, creatininase. Members of this family are creatininase (EC 3.5.2.10), an amidohydrolase that interconverts creatinine + H(2)O with creatine. It should not be confused with creatinase (EC 3.5.3.3), which hydrolyzes creatine to sarcosine plus urea. [Central intermediary metabolism, Nitrogen metabolism].
cd05283, CAD1, Cinnamyl alcohol dehydrogenases (CAD). Cinnamyl alcohol dehydrogenases (CAD), members of the medium chain dehydrogenase/reductase family, reduce cinnamaldehydes to cinnamyl alcohols in the last step of monolignal metabolism in plant cells walls. CAD binds 2 zinc ions and is NADPH- dependent. CAD family members are also found in non-plant species, e.g. in yeast where they have an aldehyde reductase activity. The medium chain dehydrogenases/reductase (MDR)/zinc-dependent alcohol dehydrogenase-like family, which contains the zinc-dependent alcohol dehydrogenase (ADH-Zn) and related proteins, is a diverse group of proteins related to the first identified member, class I mammalian ADH. MDRs display a broad range of activities and are distinguished from the smaller short chain dehydrogenases (~ 250 amino acids vs. the ~ 350 amino acids of the MDR). The MDR proteins have 2 domains: a C-terminal NAD(P) binding-Rossmann fold domain of a beta-alpha form and an N-terminal catalytic domain with distant homology to GroES. The MDR group contains a host of activities, including the founding alcohol dehydrogenase (ADH), quinone reductase, sorbitol dehydrogenase, formaldehyde dehydrogenase, butanediol DH, ketose reductase, cinnamyl reductase, and numerous others. The zinc-dependent alcohol dehydrogenases (ADHs) catalyze the NAD(P)(H)-dependent interconversion of alcohols to aldehydes or ketones. Active site zinc has a catalytic role, while structural zinc aids in stability. ADH-like proteins typically form dimers (typically higher plants, mammals) or tetramers (yeast, bacteria), and generally have 2 tightly bound zinc atoms per subunit. The active site zinc is coordinated by a histidine, two cysteines, and a water molecule. The second zinc seems to play a structural role, affects subunit interactions, and is typically coordinated by 4 cysteines.
cd03801, GT4_PimA-like, phosphatidyl-myo-inositol mannosyltransferase. This family is most closely related to the GT4 family of glycosyltransferases and named after PimA in Propionibacterium freudenreichii, which is involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIM) which are early precursors in the biosynthesis of lipomannans (LM) and lipoarabinomannans (LAM), and catalyzes the addition of a mannosyl residue from GDP-D-mannose (GDP-Man) to the position 2 of the carrier lipid phosphatidyl-myo-inositol (PI) to generate a phosphatidyl-myo-inositol bearing an alpha-1,2-linked mannose residue (PIM1). Glycosyltransferases catalyze the transfer of sugar moieties from activated donor molecules to specific acceptor molecules, forming glycosidic bonds. The acceptor molecule can be a lipid, a protein, a heterocyclic compound, or another carbohydrate residue. This group of glycosyltransferases is most closely related to the previously defined glycosyltransferase family 1 (GT1). The members of this family may transfer UDP, ADP, GDP, or CMP linked sugars. The diverse enzymatic activities among members of this family reflect a wide range of biological functions. The protein structure available for this family has the GTB topology, one of the two protein topologies observed for nucleotide-sugar-dependent glycosyltransferases. GTB proteins have distinct N- and C- terminal domains each containing a typical Rossmann fold. The two domains have high structural homology despite minimal sequence homology. The large cleft that separates the two domains includes the catalytic center and permits a high degree of flexibility. The members of this family are found mainly in certain bacteria and archaea.
TIGR01207, Glucose-1-phosphate_thymidylyltransferase_1, glucose-1-phosphate thymidylyltransferase, short form. Alternate name: dTDP-D-glucose synthase homotetramer This model describes a tightly conserved but broadly distributed subfamily (here designated as short form) of known and putative bacterial glucose-1-phosphate thymidylyltransferases. It is well characterized in several species as the first of four enzymes involved in the biosynthesis of dTDP-L-rhamnose, a cell wall constituent and a feedback inhibitor of the enzyme. [Cell envelope, Biosynthesis and degradation of surface polysaccharides and lipopolysaccharides].
cd17369, MFS_ShiA_like, Shikimate transporter and similar proteins of the Major Facilitator Superfamily. This subfamily is composed of Escherichia coli shikimate transporter (ShiA), inner membrane metabolite transport protein YhjE, and other putative metabolite transporters. ShiA is involved in the uptake of shikimate, an aromatic compound involved in siderophore biosynthesis. It has been suggested that YhjE may mediate the uptake of osmoprotectants. The ShiA-like subfamily belongs to the Metazoan Synaptic Vesicle Glycoprotein 2 (SV2) and related small molecule transporter family (SV2-like) of the Major Facilitator Superfamily (MFS) of membrane transport proteins. MFS proteins are thought to function through a single substrate binding site, alternating-access mechanism involving a rocker-switch type of movement.
cd04179, DPM_DPG-synthase_like, DPM_DPG-synthase_like is a member of the Glycosyltransferase 2 superfamily. DPM1 is the catalytic subunit of eukaryotic dolichol-phosphate mannose (DPM) synthase. DPM synthase is required for synthesis of the glycosylphosphatidylinositol (GPI) anchor, N-glycan precursor, protein O-mannose, and C-mannose. In higher eukaryotes,the enzyme has three subunits, DPM1, DPM2 and DPM3. DPM is synthesized from dolichol phosphate and GDP-Man on the cytosolic surface of the ER membrane by DPM synthase and then is flipped onto the luminal side and used as a donor substrate. In lower eukaryotes, such as Saccharomyces cerevisiae and Trypanosoma brucei, DPM synthase consists of a single component (Dpm1p and TbDpm1, respectively) that possesses one predicted transmembrane region near the C terminus for anchoring to the ER membrane. In contrast, the Dpm1 homologues of higher eukaryotes, namely fission yeast, fungi, and animals, have no transmembrane region, suggesting the existence of adapter molecules for membrane anchoring. This family also includes bacteria and archaea DPM1_like enzymes. However, the enzyme structure and mechanism of function are not well understood. The UDP-glucose:dolichyl-phosphate glucosyltransferase (DPG_synthase) is a transmembrane-bound enzyme of the endoplasmic reticulum involved in protein N-linked glycosylation. This enzyme catalyzes the transfer of glucose from UDP-glucose to dolichyl phosphate. This protein family belongs to Glycosyltransferase 2 superfamily.
cd05233, SDR_c, classical (c) SDRs. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRs are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes 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 prostaglandin dehydrogenase (PGDH) numbering). In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, PGDH numbering) and/or an Asn (Asn-107, PGDH numbering) 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. Extended SDRs have additional elements in the C-terminal region, 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. Some atypical SDRs have lost catalytic activity and/or have an unusual NAD(P)-binding motif and missing or unusual active site residues. Reactions catalyzed within the SDR family include isomerization, decarboxylation, epimerization, C=N bond reduction, dehydratase activity, dehalogenation, Enoyl-CoA reduction, and carbonyl-alcohol oxidoreduction.
TIGR03451, S-hydroxymethylmycothiol_dehydrogenase, S-(hydroxymethyl)mycothiol dehydrogenase. Members of this protein family are mycothiol-dependent formaldehyde dehydrogenase (EC 1.2.1.66). This protein is found, so far, only in the Actinobacteria (Mycobacterium sp., Streptomyces sp., Corynebacterium sp., and related species), where mycothione replaces glutathione. [Cellular processes, Detoxification].
cd06262, metallo-hydrolase-like_MBL-fold, mainly hydrolytic enzymes and related proteins which carry out various biological functions; MBL-fold metallohydrolase domain. Members of the MBL-fold metallohydrolase superfamily are mainly hydrolytic enzymes which carry out a variety of biological functions. The class B metal beta-lactamases (MBLs) for which this fold was named perform only a small fraction of the activities included in this superfamily. Activities carried out by superfamily members include class B beta-lactamases which can catalyze the hydrolysis of a wide range of beta-lactam antibiotics, hydroxyacylglutathione hydrolases (also called glyoxalase II) which hydrolyze S-d-lactoylglutathione to d-lactate in the second step of the glycoxlase system, AHL lactonases which catalyze the hydrolysis and opening of the homoserine lactone rings of acyl homoserine lactones (AHLs), persulfide dioxygenase which catalyze the oxidation of glutathione persulfide to glutathione and persulfite in the mitochondria, flavodiiron proteins which catalyze the reduction of oxygen and/or nitric oxide to water or nitrous oxide respectively, cleavage and polyadenylation specificity factors such as the Int9 and Int11 subunits of Integrator, Sdsa1-like and AtsA-like arylsulfatases, 5'-exonucleases human SNM1A and yeast Pso2p, ribonuclease J which has both 5'-3' exoribonucleolytic and endonucleolytic activity and ribonuclease Z which catalyzes the endonucleolytic removal of the 3' extension of the majority of tRNA precursors, cyclic nucleotide phosphodiesterases which decompose cyclic adenosine and guanosine 3', 5'-monophosphate (cAMP and cGMP) respectively, insecticide hydrolases, and proteins required for natural transformation competence. The diversity of biological roles is reflected in variations in the active site metallo-chemistry, for example classical members of the superfamily are di-, or less commonly mono-, zinc-ion-dependent hydrolases, human persulfide dioxygenase ETHE1 is a mono-iron binding member of the superfamily; Arabidopsis thaliana hydroxyacylglutathione hydrolases incorporates iron, manganese, and zinc in its dinuclear metal binding site, and flavodiiron proteins contains a diiron site.
cd17325, MFS_MdtG_SLC18_like, bacterial MdtG-like and eukaryotic solute carrier 18 (SLC18) family of the Major Facilitator Superfamily of transporters. This family is composed of eukaryotic solute carrier 18 (SLC18) family transporters and related bacterial multidrug resistance (MDR) transporters including several proteins from Escherichia coli such as multidrug resistance protein MdtG, from Bacillus subtilis such as multidrug resistance proteins 1 (Bmr1) and 2 (Bmr2), and from Staphylococcus aureus such as quinolone resistance protein NorA. The family also includes Escherichia coli arabinose efflux transporters YfcJ and YhhS. MDR transporters are drug/H+ antiporters (DHA) that mediate the efflux of a variety of drugs and toxic compounds, and confer resistance to these compounds. The SLC18 transporter family includes vesicular monoamine transporters (VAT1 and VAT2), vesicular acetylcholine transporter (VAChT), and SLC18B1, which is proposed to be a vesicular polyamine transporter (VPAT). The MdtG/SLC18 family belongs to the Major Facilitator Superfamily (MFS) of membrane transport proteins, which are thought to function through a single substrate binding site, alternating-access mechanism involving a rocker-switch type of movement.
cd05256, UDP_AE_SDR_e, UDP-N-acetylglucosamine 4-epimerase, extended (e) SDRs. This subgroup contains UDP-N-acetylglucosamine 4-epimerase of Pseudomonas aeruginosa, WbpP, an extended SDR, that catalyzes the NAD+ dependent conversion of UDP-GlcNAc and UDPGalNA to UDP-Glc and UDP-Gal. This subgroup has the characteristic active site tetrad and NAD-binding motif of the extended SDRs. Extended SDRs are distinct from classical SDRs. In addition to the Rossmann fold (alpha/beta folding pattern with a central beta-sheet) core region typical of all SDRs, extended SDRs have a less conserved C-terminal extension of approximately 100 amino acids. Extended SDRs are a diverse collection of proteins, and include isomerases, epimerases, oxidoreductases, and lyases; they typically have a TGXXGXXG cofactor binding motif. 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. 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. 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.
cd09643, Csn1, CRISPR/Cas system-associated protein Cas9. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and associated Cas proteins comprise a system for heritable host defense by prokaryotic cells against phage and other foreign DNA; Very large protein containing McrA/HNH-nuclease related domain and a RuvC-like nuclease domain; signature gene for type II.
COG4988, CydD, ABC-type transport system involved in cytochrome bd biosynthesis, ATPase and permease components [Energy production and conversion / Posttranslational modification, protein turnover, chaperones].
cd19542, CT_NRPS-like, Terminal Condensation (CT)-like domains of nonribosomal peptide synthetases (NRPSs). Unlike bacterial NRPS, which typically have specialized terminal thioesterase (TE) domains to cyclize peptide products, many fungal NRPSs employ a terminal condensation-like (CT) domain to produce macrocyclic peptidyl products (e.g. cyclosporine and echinocandin). Domains in this subfamily (which includes both terminal and non-terminal domains) typically have a non-canonical conserved [SN]HxxxDx(14)Y motif at their active site compared to the standard Condensation (C) domain active site motif (HHxxxD). C-domains of NRPSs catalyze peptide bond formation within (usually) large multi-modular enzymatic complexes. NRPS can use a large variety of acyl monomers (approximately 500 different possible monomer substrates as opposed to the 20 standard amino acids in ribosomal protein synthesis) to construct bioactive secondary metabolites of 2 to 18 units long (with various activities such as antibiotic, antifungal, antitumor and immunosuppression). There are various subtypes of C-domains such as the LCL-type which catalyzes peptide bond formation between two L-amino acids, the DCL-type which links an L-amino acid to the D-amino acid at the end of a growing peptide, starter C-domains which acylate the first amino acid with a beta-hydroxy carboxylic acid, and heterocyclization (Cyc) domains which catalyze both peptide bond formation and cyclization of Cys, Ser, or Thr residues. Typically, an NRPS module consists of an adenylation domain, a peptidyl carrier protein (PCP) domain (also known as thiolation (T) domain) and a C-domain. NRPS modules may also include specialized domains such as the terminal-module thioesterase (Te) domain that releases the product via hydrolysis or macrocyclization and any of various C-domain family members such as the epimerization (E) domain, the ester-bond forming C-domain, dual E/C (epimerization and condensation) domains, and the X-domain.
pfam01654, Cyt_bd_oxida_I, Cytochrome bd terminal oxidase subunit I. This family are the alternative oxidases found in many bacteria which oxidize ubiquinol and reduce oxygen as part of the electron transport chain. This family is the subunit I of the oxidase E. coli has two copies of the oxidase, bo and bd', both of which are represented here In some nitrogen fixing bacteria, e.g. Klebsiella pneumoniae this oxidase is responsible for removing oxygen in microaerobic conditions, making the oxidase required for nitrogen fixation. This subunit binds a single b-haem, through ligands at His186 and Met393 (using SW:P11026 numbering). In addition His19 is a ligand for the haem b found in subunit II.
TIGR02868, ABC_transporter_ATP-binding_protein, thiol reductant ABC exporter, CydC subunit. The gene pair cydCD encodes an ABC-family transporter in which each gene contains an N-terminal membrane-spanning domain (pfam00664) and a C-terminal ATP-binding domain (pfam00005). In E. coli these genes were discovered as mutants which caused the terminal heme-copper oxidase complex cytochrome bd to fail to assemble. Recent work has shown that the transporter is involved in export of redox-active thiol compounds such as cysteine and glutathione. The linkage to assembly of the cytochrome bd complex is further supported by the conserved operon structure found outside the gammaproteobacteria (cydABCD) containing both the transporter and oxidase genes components. The genes used as the seed members for this model are all either found in the gammproteobacterial context or the CydABCD context. All members of this family scoring above trusted at the time of its creation were from genomes which encode a cytochrome bd complex.
TIGR02121, Osmoregulated_proline_transporter, sodium/proline symporter. This family consists of the sodium/proline symporter (proline permease) from a number of Gram-negative and Gram-positive bacteria and from the archaeal genus Methanosarcina. Using the related pantothenate permease as an outgroup, candidate sequences from Bifidobacterium longum and several from archaea are found to be outside the clade defined by known proline permeases. These sequences, scoring between 570 and -40, define the range between trusted and noise cutoff scores. [Transport and binding proteins, Amino acids, peptides and amines].
cd03425, MutT_pyrophosphohydrolase, The MutT pyrophosphohydrolase is a prototypical Nudix hydrolase that catalyzes the hydrolysis of nucleoside and deoxynucleoside triphosphates (NTPs and dNTPs) by substitution at a beta-phosphorus to yield a nucleotide monophosphate (NMP) and inorganic pyrophosphate (PPi). This enzyme requires two divalent cations for activity; one coordinates the phosphoryl groups of the NTP/dNTP substrate, and the other coordinates to the enzyme. It also contains the Nudix motif, a highly conserved 23-residue block (GX5EX7REUXEEXGU, where U = I, L or V), that functions as metal binding and catalytic site. MutT pyrophosphohydrolase is important in preventing errors in DNA replication by hydrolyzing mutagenic nucleotides such as 8-oxo-dGTP (a product of oxidative damage), which can mispair with template adenine during DNA replication, to guanine nucleotides.
pfam11907, DUF3427, Domain of unknown function (DUF3427). This presumed domain is functionally uncharacterized. This domain is found in bacteria and archaea. This domain is typically between 243 to 275 amino acids in length. This domain is found associated with pfam04851, pfam00271.
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')
