cd01400, 6PGL, 6PGL: 6-Phosphogluconolactonase (6PGL) subfamily; 6PGL catalyzes the second step of the oxidative phase of the pentose phosphate pathway, the hydrolyzation of 6-phosphoglucono-1,5-lactone (delta form) to 6-phosphogluconate. 6PGL is thought to guard against the accumulation of the delta form of the lactone, which may be toxic through its reaction with endogenous cellular nucleophiles.
cd07133, ALDH_CALDH_CalB, Coniferyl aldehyde dehydrogenase-like. Coniferyl aldehyde dehydrogenase (CALDH, EC=1.2.1.68) of Pseudomonas sp. strain HR199 (CalB) which catalyzes the NAD+-dependent oxidation of coniferyl aldehyde to ferulic acid, and similar sequences, are present in this CD.
pfam12625, Arabinose_bd, Arabinose-binding domain of AraC transcription regulator, N-term. AraC is a bacterial transcriptional regulatory protein with a DNA-binding domain at the C-terminus, HTH_AraC, pfam00165, and this dimerization domain which harbours the arabinose-binding pocket at the N-terminus. AraC positively and negatively regulates expression of the proteins required for the uptake and catabolism of the sugar L-arabinose 1,2,3].
cd09008, MTAN, 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidases. This subfamily includes both bacterial and plant 5'-methylthioadenosine/S-adenosylhomocysteine (MTA/SAH) nucleosidases (MTANs): bacterial MTANs show comparable efficiency in hydrolyzing MTA and SAH, while plant enzymes are highly specific for MTA and are unable to metabolize SAH or show significantly reduced activity towards SAH. MTAN is involved in methionine and S-adenosyl-methionine recycling, polyamine biosynthesis, and bacterial quorum sensing. This subfamily belongs to the nucleoside phosphorylase-I (NP-I) family, whose members accept a range of purine nucleosides as well as the pyrimidine nucleoside uridine. The NP-1 family includes phosphorolytic nucleosidases, such as purine nucleoside phosphorylase (PNPs, EC. 2.4.2.1), uridine phosphorylase (UP, EC 2.4.2.3), and 5'-deoxy-5'-methylthioadenosine phosphorylase (MTAP, EC 2.4.2.28), and hydrolytic nucleosidases, such as AMP nucleosidase (AMN, EC 3.2.2.4), and 5'-methylthioadenosine/S-adenosylhomocysteine (MTA/SAH) nucleosidase (MTAN, EC 3.2.2.16). The NP-I family is distinct from nucleoside phosphorylase-II, which belongs to a different structural family.
cd00829, SCP-x_thiolase, Thiolase domain associated with sterol carrier protein (SCP)-x isoform and related proteins; SCP-2 has multiple roles in intracellular lipid circulation and metabolism. The N-terminal presequence in the SCP-x isoform represents a peroxisomal 3-ketacyl-Coa thiolase specific for branched-chain acyl CoAs, which is proteolytically cleaved from the sterol carrier protein.
cd05371, HSD10-like_SDR_c, 17hydroxysteroid dehydrogenase type 10 (HSD10)-like, classical (c) SDRs. HSD10, also known as amyloid-peptide-binding alcohol dehydrogenase (ABAD), was previously identified as a L-3-hydroxyacyl-CoA dehydrogenase, HADH2. In fatty acid metabolism, HADH2 catalyzes the third step of beta-oxidation, the conversion of a hydroxyl to a keto group in the NAD-dependent oxidation of L-3-hydroxyacyl CoA. In addition to alcohol dehydrogenase and HADH2 activites, HSD10 has steroid dehydrogenase activity. Although the mechanism is unclear, HSD10 is implicated in the formation of amyloid beta-petide in the brain (which is linked to the development of Alzheimer's disease). Although HSD10 is normally concentrated in the mitochondria, in the presence of amyloid beta-peptide it translocates into the plasma membrane, where it's action may generate cytotoxic aldehydes and may lower estrogen levels through its use of 17-beta-estradiol as a substrate. HSD10 is a member of the SRD family, but differs from other SDRs by the presence of two insertions of unknown function. 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 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering). In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-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.
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')
