pfam04011, LemA, LemA family. The members of this family are related to the LemA protein. LemA contains an amino terminal predicted transmembrane helix. It has been predicted that the small amino terminus is extracellular. The exact molecular function of this protein is uncertain.
cd01043, DPS, DPS protein, ferritin-like diiron-binding domain. DPS (DNA Protecting protein under Starved conditions) domain is a member of a broad superfamily of ferritin-like diiron-carboxylate proteins. Some DPS proteins nonspecifically bind DNA, protecting it from cleavage caused by reactive oxygen species such as the hydroxyl radicals produced during oxidation of Fe(II) by hydrogen peroxide. These proteins assemble into dodecameric structures, some form DPS-DNA co-crystalline complexes, and possess iron and H2O2 detoxification capabilities. Expression of DPS is induced by oxidative or nutritional stress, including metal ion starvation. Members of the DPS family are homopolymers formed by 12 four-helix bundle subunits that assemble with 23 symmetry into a hollow shell. The DPS ferroxidase site is unusual in that it is not located in a four-helix bundle as in ferritin, but is shared by 2-fold symmetry-related subunits providing the iron ligands. Many DPS sequences (e.g., E. coli) display an N-terminal extension of variable length that contains two or three positively charged lysine residues that extends into the solvent and is thought to play an important role in the stabilization of the complex with DNA. DPS Listeria Flp, Bacillus anthracis Dlp-1 and Dlp-2, and Helicobacter pylori HP-NAP which lack the N-terminal extension, do not bind DNA. DPS proteins from Helicobacter pylori, Treponema pallidum, and Borrelia burgdorferi are highly immunogenic.
cd04254, AAK_UMPK-PyrH-Ec, UMP kinase (UMPK)-Ec, the microbial/chloroplast uridine monophosphate kinase (uridylate kinase) enzyme that catalyzes UMP phosphorylation and plays a key role in pyrimidine nucleotide biosynthesis; regulation of this process is via feed-back control and via gene repression of carbamoyl phosphate synthetase (the first enzyme of the pyrimidine biosynthesis pathway). The UMP kinase of E. coli (Ec) is known to function as a homohexamer, with GTP and UTP being allosteric effectors. Like other related enzymes (carbamate kinase, aspartokinase, and N-acetylglutamate kinase) the E. coli and most bacterial and chloroplast UMPKs (this CD) have a conserved, N-terminal, lysine residue proposed to function in the catalysis of the phosphoryl group transfer, whereas most archaeal UMPKs appear to lack this residue and the Pyrococcus furiosus structure has an additional Mg ion bound to the ATP molecule which is proposed to function as the catalysis instead. Members of this CD belong to the Amino Acid Kinase Superfamily (AAK).
cd17262, RMtype1_S_Aco12261I-TRD2-CR2, Type I restriction-modification system specificity (S) subunit Target Recognition Domain-ConseRved domain (TRD-CR), similar to Aminobacterium colombiense DSM 12261 S subunit (S.Aco12261I) TRD2-CR2 and Moraxella catarrhalis S subunit (S.Mca353ORF290P) TRD2-CR2. Aminobacterium colombiense DSM 12261 S subunit (S.Aco12261I) recognizes 5'... GCANNNNNNTGT ... 3', and Moraxella catarrhalis S subunit (S.Mca353ORF290P) recognizes 5'... CAAGNNNNNNTGT ... 3'. The restriction-modification (RM) system S subunit consists of two variable target recognition domains (TRD1 and 2) and two conserved regions (CR1 and CR2) which separate the TRDs. The TRDs each bind to different specific sequences in the DNA. RM systems protect a bacterial cell against invasion of foreign DNA by endonucleolytic cleavage of DNA that lacks a site specific modification. The host genome is protected from cleavage by methylation of specific nucleotides in the target sites. In type I systems, both restriction and modification activities are present in one enzyme complex composed of one DNA specificity (S) subunit (this family), two modification (M) subunits and two restriction (R) subunits. This model contains both TRD1-CR1 and TRD2-CR2. It may also include TRD-CR-like sequence-recognition domains of various type II restriction enzymes and methyltransferases and type I DNA methyltransferases.
pfam01732, DUF31, Putative peptidase (DUF31). This domain has no known function. It is found in various hypothetical proteins and putative lipoproteins from mycoplasmas. It appears to be related to the superfamily of trypsin peptidases and so may have a peptidase function.
cd07516, HAD_Pase, phosphatase, similar to Escherichia coli Cof and Thermotoga maritima TM0651; belongs to the haloacid dehalogenase-like superfamily. Escherichia coli Cof is involved in the hydrolysis of HMP-PP (4-amino-2-methyl-5-hydroxymethylpyrimidine pyrophosphate, an intermediate in thiamin biosynthesis), Cof also has phosphatase activity against the coenzymes pyridoxal phosphate (PLP) and FMN. Thermotoga maritima TM0651 acts as a phosphatase with a phosphorylated carbohydrate molecule as a possible substrate. Escherichia coli YbhA is also a member of this family and catalyzes the dephosphorylation of PLP, YbhA can also hydrolyze erythrose-4-phosphate and fructose-1,6-bis-phosphate. Members of this family belong 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.
cd04688, Nudix_Hydrolase_29, Members of the Nudix hydrolase superfamily catalyze 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 and contain a highly conserved 23-residue nudix motif (GX5EX7REUXEEXGU, where U = I, L or V), which functions as a metal binding and catalytic site. Substrates of nudix hydrolases 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 & "house-cleaning" enzymes. Substrate specificity is used to define 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.
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')
