TIGR02227, Inactive_signal_peptidase_IA., signal peptidase I, bacterial type. This model represents signal peptidase I from most bacteria. Eukaryotic sequences are likely organellar. Several bacteria have multiple paralogs, but these represent isozymes of signal peptidase I. Virtually all known bacteria may be presumed to A related model finds a simlar protein in many archaea and a few bacteria, as well as a microsomal (endoplasmic reticulum) protein in eukaryotes. [Protein fate, Protein and peptide secretion and trafficking].
pfam05138, PaaA_PaaC, Phenylacetic acid catabolic protein. This family includes proteins such as PaaA and PaaC that are part of a catabolic pathway of phenylacetic acid. These proteins may form part of a dioxygenase complex.
pfam14023, DUF4239, Protein of unknown function (DUF4239). This family of proteins is functionally uncharacterized. This family of proteins is found in bacteria and eukaryotes. Proteins in this family are typically between 254 and 270 amino acids in length.
TIGR02160, 12-phenylacetyl-CoA_epoxidase_subunit_E, phenylacetate-CoA oxygenase/reductase, PaaK subunit. Phenylacetate-CoA oxygenase is comprised of a five gene complex responsible for the hydroxylation of phenylacetate-CoA (PA-CoA) as the second catabolic step in phenylacetic acid (PA) degradation. Although the exact function of this enzyme has not been determined, it has been shown to be required for phenylacetic acid degradation and has been proposed to function in a multicomponent oxygenase acting on phenylacetate-CoA. [Energy metabolism, Other].
pfam13396, PLDc_N, Phospholipase_D-nuclease N-terminal. This family is often found at the very N-terminus of proteins from the phospholipase_D-nuclease family, PLDc, pfam00614. However, a large number of members are full-length within this family.
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.
TIGR02159, Putative_12-phenylacetyl-CoA_epoxidase_subunit_D, phenylacetate-CoA oxygenase, PaaJ subunit. Phenylacetate-CoA oxygenase is comprised of a five gene complex responsible for the hydroxylation of phenylacetate-CoA (PA-CoA) as the second catabolic step in phenylacetic acid (PA) degradation. Although the exact function of this enzyme has not been determined, it has been shown to be required for phenylacetic acid degradation and has been proposed to function in a multicomponent oxygenase acting on phenylacetate-CoA. [Energy metabolism, Other].
cd06193, siderophore_interacting, Siderophore interacting proteins share the domain structure of the ferredoxin reductase like family. Siderophores are produced in various bacteria (and some plants) to extract iron from hosts. Binding constants are high, so iron can be pilfered from transferrin and lactoferrin for bacterial uptake, contributing to pathogen virulence. Ferredoxin reductase (FNR), an FAD and NAD(P) binding protein, was intially identified as a chloroplast reductase activity, catalyzing the electron transfer from reduced iron-sulfur protein ferredoxin to NADP+ as the final step in the electron transport mechanism of photosystem I. FNR transfers electrons from reduced ferredoxin to FAD (forming FADH2 via a semiquinone intermediate) and then transfers a hydride ion to convert NADP+ to NADPH. FNR has since been shown to utilize a variety of electron acceptors and donors and has a variety of physiological functions including nitrogen assimilation, dinitrogen fixation, steroid hydroxylation, fatty acid metabolism, oxygenase activity, and methane assimilation in a variety of organisms. FNR has an NAD(P)-binding sub-domain of the alpha/beta class and a discrete (usually N-terminal) flavin sub-domain which vary in orientation with respect to the NAD(P) binding domain. The N-terminal moeity may contain a flavin prosthetic group (as in flavoenzymes) or use flavin as a substrate. Because flavins such as FAD can exist in oxidized, semiquinone (one-electron reduced), or fully reduced hydroquinone forms, FNR can interact with one and two electron carriers. FNR has a strong preference for NADP(H) vs NAD(H).
cd06558, crotonase-like, Crotonase/Enoyl-Coenzyme A (CoA) hydratase superfamily. This superfamily contains a diverse set of enzymes including enoyl-CoA hydratase, napthoate synthase, methylmalonyl-CoA decarboxylase, 3-hydoxybutyryl-CoA dehydratase, and dienoyl-CoA isomerase. Many of these play important roles in fatty acid metabolism. In addition to a conserved structural core and the formation of trimers (or dimers of trimers), a common feature in this superfamily is the stabilization of an enolate anion intermediate derived from an acyl-CoA substrate. This is accomplished by two conserved backbone NH groups in active sites that form an oxyanion hole.
cd00751, thiolase, Thiolase are ubiquitous enzymes that catalyze the reversible thiolytic cleavage of 3-ketoacyl-CoA into acyl-CoA and acetyl-CoA, a 2-step reaction involving a covalent intermediate formed with a catalytic cysteine. They are found in prokaryotes and eukaryotes (cytosol, microbodies and mitochondria). There are 2 functional different classes: thiolase-I (3-ketoacyl-CoA thiolase) and thiolase-II (acetoacetyl-CoA thiolase). Thiolase-I can cleave longer fatty acid molecules and plays an important role in the beta-oxidative degradation of fatty acids. Thiolase-II has a high substrate specificity. Although it can cleave acetoacyl-CoA, its main function is the synthesis of acetoacyl-CoA from two molecules of acetyl-CoA, which gives it importance in several biosynthetic pathways.
TIGR00711, Uncharacterized_MFS-type_transporter_YhcA, drug resistance transporter, EmrB/QacA subfamily. This subfamily of drug efflux proteins, a part of the major faciliator family, is predicted to have 14 potential membrane-spanning regions. Members with known activities include EmrB (multiple drug resistance efflux pump) in E. coli, FarB (antibacterial fatty acid resistance) in Neisseria gonorrhoeae, TcmA (tetracenomycin C resistance) in Streptomyces glaucescens, etc. In most cases, the efflux pump is described as having a second component encoded in the same operon, such as EmrA of E. coli. [Cellular processes, Toxin production and resistance, Transport and binding proteins, Other].
cd07205, Pat_PNPLA6_PNPLA7_NTE1_like, Patatin-like phospholipase domain containing protein 6, protein 7, and fungal NTE1. Patatin-like phospholipase domain containing protein 6 (PNPLA6) and protein 7 (PNPLA7) are included in this family. PNPLA6 is commonly known as Neuropathy Target Esterase (NTE). NTE has at least two functional domains: the N-terminal domain putatively regulatory domain and the C-terminal catalytic domain which shows esterase activity. NTE shows phospholipase activity for lysophosphatidylcholine (LPC) and phosphatidylcholine (PC). Exposure of NTE to organophosphates leads to organophosphate-induced delayed neurotoxicity (OPIDN). OPIDN is a progressive neurological condition that is characterized by weakness, paralysis, pain, and paresthesia. PNPLA7 is an insulin-regulated phospholipase that is homologus to Neuropathy Target Esterase (NTE or PNPLA6) and is also known as NTE-related esterase (NRE). Human NRE is predominantly expressed in prostate, white adipose, and pancreatic tissue. NRE hydrolyzes sn-1 esters in lysophosphatidylcholine and lysophosphatidic acid, but shows no lipase activity with substrates like triacylglycerols (TG), cholesteryl esters, retinyl esters (RE), phosphatidylcholine (PC), or monoacylglycerol (MG). This family includes subfamily of PNPLA6 (NTE) and PNPLA7 (NRE)-like phospholipases.
cd12830, MtCorA-like, Mycobacterium tuberculosis CorA-like subfamily. This bacterial subfamily belongs to the Thermotoga maritima CorA (TmCorA)-like family of the MIT superfamily of essential membrane proteins involved in transporting divalent cations (uptake or efflux) across membranes. This subfamily includes the Mg2+ transporter Mycobacterium tuberculosis CorA (which also transports Co2+). Thermotoga maritima CorA forms funnel-shaped homopentamers, the tip of the funnel is formed from two C-terminal transmembrane (TM) helices from each monomer, and the large opening of the funnel from the N-terminal cytoplasmic domains. The GMN signature motif of the MIT superfamily occurs just after TM1, mutation within this motif is known to abolish Mg2+ transport by a related protein, Saccharomyces cerevisiae Alr1p. Natural variants in this signature sequence may be associated with the transport of different divalent cations. The functional diversity of the MIT superfamily may also be due to minor structural differences regulating gating, substrate selection, and transport.
cd04766, HTH_HspR, Helix-Turn-Helix DNA binding domain of the HspR transcription regulator. Helix-turn-helix (HTH) transcription regulator HspR, N-terminal domain. Heat shock protein regulators (HspR) have been shown to regulate expression of specific regulons in response to high temperature or high osmolarity in Streptomyces and Helicobacter, respectively. These proteins share the N-terminal DNA binding domain with other transcription regulators of the MerR superfamily that promote transcription by reconfiguring the spacer between the -35 and -10 promoter elements. A typical MerR regulator is comprised of distinct domains that harbor the regulatory (effector-binding) site and the active (DNA-binding) site. Their conserved N-terminal domains contain predicted winged HTH motifs that mediate DNA binding, while the dissimilar C-terminal domains bind specific coactivator molecules.
cd01014, nicotinamidase_related, Nicotinamidase_ related amidohydrolases. Cysteine hydrolases of unknown function that share the catalytic triad with other amidohydrolases, like nicotinamidase, which converts nicotinamide to nicotinic acid and ammonia.
cd00446, GrpE, nucleotide exchange factor GrpE. GrpE is the adenine nucleotide exchange factor of DnaK (Hsp70)-type ATPases. In bacteria, the DnaK-DnaJ-GrpE (KJE) chaperone system functions at the fulcrum of protein homeostasis. GrpE participates actively in response to heat shock by preventing aggregation of stress-denatured proteins; unfolded proteins initially bind to DnaJ, the J-domain ATPase-activating protein (Hsp40 family), whereupon DnaK hydrolyzes its bound ATP, resulting in a stable complex. The GrpE dimer binds to the ATPase domain of Hsp70 catalyzing the dissociation of ADP, which enables rebinding of ATP, one step in the Hsp70 reaction cycle in protein folding. In eukaryotes, only the mitochondrial Hsp70, not the cytosolic form, is GrpE dependent. Over-expression of Hsp70 molecular chaperones is important in suppressing toxicity of aberrantly folded proteins that occur in Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis, as well as several polyQ-diseases such as Huntington's disease and ataxias.
cd00413, Glyco_hydrolase_16, glycosyl hydrolase family 16. The O-Glycosyl hydrolases are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A glycosyl hydrolase classification system based on sequence similarity has led to the definition of more than 95 different families inlcuding glycosyl hydrolase family 16. Family 16 includes lichenase, xyloglucan endotransglycosylase (XET), beta-agarase, kappa-carrageenase, endo-beta-1,3-glucanase, endo-beta-1,3-1,4-glucanase, and endo-beta-galactosidase, all of which have a conserved jelly roll fold with a deep active site channel harboring the catalytic residues.
pfam05175, MTS, Methyltransferase small domain. This domain is found in ribosomal RNA small subunit methyltransferase C as well as other methyltransferases.
TIGR00711, Uncharacterized_MFS-type_transporter_YhcA, drug resistance transporter, EmrB/QacA subfamily. This subfamily of drug efflux proteins, a part of the major faciliator family, is predicted to have 14 potential membrane-spanning regions. Members with known activities include EmrB (multiple drug resistance efflux pump) in E. coli, FarB (antibacterial fatty acid resistance) in Neisseria gonorrhoeae, TcmA (tetracenomycin C resistance) in Streptomyces glaucescens, etc. In most cases, the efflux pump is described as having a second component encoded in the same operon, such as EmrA of E. coli. [Cellular processes, Toxin production and resistance, Transport and binding proteins, Other].
cd01300, YtcJ_like, YtcJ_like metal dependent amidohydrolases. YtcJ is a Bacillus subtilis ORF of unknown function. The Arabidopsis homolog LAF3 has been identified as a factor required for photochrome A signalling.
