cd05251, NmrA_like_SDR_a, NmrA (a transcriptional regulator) and HSCARG (an NADPH sensor) like proteins, atypical (a) SDRs. NmrA and HSCARG like proteins. NmrA is a negative transcriptional regulator of various fungi, involved in the post-translational modulation of the GATA-type transcription factor AreA. NmrA lacks the canonical GXXGXXG NAD-binding motif and has altered residues at the catalytic triad, including a Met instead of the critical Tyr residue. NmrA may bind nucleotides but appears to lack any dehydrogenase activity. HSCARG has been identified as a putative NADP-sensing molecule, and redistributes and restructures in response to NADPH/NADP ratios. Like NmrA, it lacks most of the active site residues of the SDR family, but has an NAD(P)-binding motif similar to the extended SDR family, GXXGXXG. 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. Atypical SDRs are distinct from classical SDRs. 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.
TIGR03508, decahem_SO, decaheme c-type cytochrome, DmsE family. Members of this family are small, decaheme c-type cytochromes, related DmsE of Shewanella oneidensis MR-1, which has been shown to be part of an anaerobic dimethyl sulfoxide reductase.
TIGR01730, COG0845:_Membrane-fusion_protein, RND family efflux transporter, MFP subunit. This model represents the MFP (membrane fusion protein) component of the RND family of transporters. RND refers to Resistance, Nodulation, and cell Division. It is, in part, a subfamily of pfam00529 (Pfam release 7.5) but hits substantial numbers of proteins missed by that model. The related HlyD secretion protein, for which pfam00529 is named, is outside the scope of this model. Attributed functions imply outward transport. These functions include nodulation, acriflavin resistance, heavy metal efflux, and multidrug resistance proteins. Most members of this family are found in Gram-negative bacteria. The proposed function of MFP proteins is to bring the inner and outer membranes together and enable transport to the outside of the outer membrane. Note, however, that a few members of this family are found in Gram-positive bacteria, where there is no outer membrane. [Transport and binding proteins, Unknown substrate].
cd01949, GGDEF, Diguanylate-cyclase (DGC) or GGDEF domain. Diguanylate-cyclase (DGC) or GGDEF domain: Originally named after a conserved residue pattern, and initially described as a domain of unknown function 1 (DUF1). This domain is widely present in bacteria, linked to a wide range of non-homologous domains in a variety of cell signaling proteins. The domain shows homology to the adenylyl cyclase catalytic domain. This correlates with the functional information available on two GGDEF-containing proteins, namely diguanylate cyclase and phosphodiesterase A of Acetobacter xylinum, both of which regulate the turnover of cyclic diguanosine monophosphate. Together with the EAL domain, GGDEF might be involved in regulating cell surface adhesion in bacteria.
pfam11279, DUF3080, Protein of unknown function (DUF3080). Some members in this family of proteins are annotated as lipoproteins however this cannot be confirmed. Currently this family has no known function.
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.
cd04301, NAT_SF, N-Acyltransferase superfamily: Various enzymes that characteristically catalyze the transfer of an acyl group to a substrate. NAT (N-Acyltransferase) is a large superfamily of enzymes that mostly catalyze the transfer of an acyl group to a substrate and are implicated in a variety of functions, ranging from bacterial antibiotic resistance to circadian rhythms in mammals. Members include GCN5-related N-Acetyltransferases (GNAT) such as Aminoglycoside N-acetyltransferases, Histone N-acetyltransferase (HAT) enzymes, and Serotonin N-acetyltransferase, which catalyze the transfer of an acetyl group to a substrate. The kinetic mechanism of most GNATs involves the ordered formation of a ternary complex: the reaction begins with Acetyl Coenzyme A (AcCoA) binding, followed by binding of substrate, then direct transfer of the acetyl group from AcCoA to the substrate, followed by product and subsequent CoA release. Other family members include Arginine/ornithine N-succinyltransferase, Myristoyl-CoA: protein N-myristoyltransferase, and Acyl-homoserinelactone synthase which have a similar catalytic mechanism but differ in types of acyl groups transferred. Leucyl/phenylalanyl-tRNA-protein transferase and FemXAB nonribosomal peptidyltransferases which catalyze similar peptidyltransferase reactions are also included.
TIGR03507, decahem_SO1788, decaheme c-type cytochrome, OmcA/MtrC family. The protein SO_1778 (MtrC) of Shewanella oneidensis MR-1, and its paralog SO_1779 (OmcA), with which it intteracts, are large decaheme proteins, about 900 amino acids in length, involved in the use of manganese [Mn(III/IV)] and iron [Fe(III)] as terminal electron acceptors. This model represents these and similar decaheme proteins, found also in Rhodoferax ferrireducens DSM 15236, Aeromonas hydrophila ATCC7966, and a few other bacterial species. [Energy metabolism, Electron transport].
cd03041, GST_N_2GST_N, GST_N family, 2 repeats of the N-terminal domain of soluble GSTs (2 GST_N) subfamily; composed of uncharacterized proteins. GSTs are cytosolic dimeric proteins involved in cellular detoxification by catalyzing the conjugation of glutathione (GSH) with a wide range of endogenous and xenobiotic alkylating agents, including carcinogens, therapeutic drugs, environmental toxins, and products of oxidative stress. GSTs also show GSH peroxidase activity and are involved in the synthesis of prostaglandins and leukotrienes. The GST fold contains an N-terminal TRX-fold domain and a C-terminal alpha helical domain, with an active site located in a cleft between the two domains.
pfam11854, MtrB_PioB, Putative outer membrane beta-barrel porin, MtrB/PioB. MtrB-PioB is a family of bacterial putative outer membrane porins. This family, is secreted as part of the pio (phototrophic iron oxidation) operon that has been found to couple the oxidation of ferrous iron [Fe(II)] to reductive CO2 fixation using light energy. PioABC is found in Rhodopseudomonas palustris and MtrB-PioB is likely to be a beta-barrel porin. Similar to other outer membrane porins, PioB and MtrB are predicted to have long loops protruding into the extracellular space and short turns on the periplasmic side.
pfam01551, Peptidase_M23, Peptidase family M23. Members of this family are zinc metallopeptidases with a range of specificities. The peptidase family M23 is included in this family, these are Gly-Gly endopeptidases. Peptidase family M23 are also endopeptidases. This family also includes some bacterial lipoproteins for which no proteolytic activity has been demonstrated. This family also includes leukocyte cell-derived chemotaxin 2 (LECT2) proteins. LECT2 is a liver-specific protein which is thought to be linked to hepatocyte growth although the exact function of this protein is unknown.
pfam03264, Cytochrom_NNT, NapC/NirT cytochrome c family, N-terminal region. Within the NapC/NirT family of cytochrome c proteins, some members, such as NapC and NirT, bind four haem groups, while others, such as TorC, bind five haems. This family aligns the common N-terminal region that contains four haem-binding C-X(2)-CH motifs.
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')
