cd00429, RPE, Ribulose-5-phosphate 3-epimerase (RPE). This enzyme catalyses the interconversion of D-ribulose 5-phosphate (Ru5P) into D-xylulose 5-phosphate, as part of the Calvin cycle (reductive pentose phosphate pathway) in chloroplasts and in the oxidative pentose phosphate pathway. In the Calvin cycle Ru5P is phosphorylated by phosphoribulose kinase to ribulose-1,5-bisphosphate, which in turn is used by RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) to incorporate CO2 as the central step in carbohydrate synthesis.
pfam01103, Bac_surface_Ag, Surface antigen. This entry includes the following surface antigens; D15 antigen from H.influenzae, OMA87 from P.multocida, OMP85 from N.meningitidis and N.gonorrhoeae. The family also includes a number of eukaryotic proteins that are members of the UPF0140 family. There also appears to be a relationship to pfam03865 (personal obs: C Yeats). In eukaryotes, it appears that these proteins are not surface antigens; S. cerevisiae YNL026W (SAM50) is an essential component of the Sorting and Assembly Machinery (SAM) of the mitochondrial outer membrane. The protein was localized to the mitochondria.
TIGR04131, conserved_hypothetical_protein, gliding motility-associated C-terminal domain. This model describes a protein homology domain unique to, and greatly expanded in, the Bacteriodetes. Species in this lineage include several, such as Cytophaga hutchinsonii and Flavobacterium johnsoniae, that exhibit a poorly understood rapid gliding phenotype. Several members of this protein family are found in operons with other genes whose loss leads to a loss a this motility. Proteins with this domain frequently pair with members of family TIGR03519, whether one such pair or many occur in a genome. More than 30 members may occur in one genome.
pfam13778, DUF4174, Domain of unknown function (DUF4174). This domain of unknown function is found in a putative tumor suppressor gene and in a ligand for the the urokinase-type plasminogen activator receptor, which plays a role in cellular migration and adhesion.
TIGR04018, thioredoxin_reductase, putative bacillithiol system oxidoreductase, YpdA family. Members of this protein family, including YpdA from Bacillus subtilis, are apparent oxidoreductases present only in species with an active bacillithiol system. They have been suggested actually to be thiol disulfide oxidoreductases (TDOR), although the evidence is incomplete. [Unknown function, Enzymes of unknown specificity].
cd15242, 7tm_Proteorhodopsin, green- and blue-light absorbing proteorhodopsins, member of the seven-transmembrane GPCR superfamily. This subgroup represents blue-light absorbing and green-light absorbing proteorhodopsins (PRs), which act as a light-driven proton pump that plays a major role in supplying light energy for phototropic marine microorganisms, by a mechanism similar to that of bacteriorhodopsin. PRs are found in most marine bacteria in surface waters, as well as in archaea and eukaryotes. They belong to the microbial rhodopsin family, also known as type 1 rhodopsins, comprising the light-driven inward chloride pump halorhodopsin (HR), the light-gated cation channel channelrhodopsin (ChR), the light-sensor activating transmembrane transducer protein sensory rhodopsin II (SRII), the light-sensor activating soluble transducer protein Anabaena sensory rhodopsin (ASR), and the other light-driven proton pumps such as bacteriorhodopsin (BR). They have been found in various single-celled microorganisms from all three domains of life, including halophile archaea, gamma-proteobacteria, cyanobacteria, fungi, and green algae. While microbial (type 1) and animal (type 2) rhodopsins have no sequence similarity with each other, they share a common architecture consisting of seven-transmembrane alpha-helices (TM) connected by extracellular loops and intracellular loops. Both types of rhodopsins consist of opsin and a covalently attached retinal (the aldehyde of vitamin A), a photoreactive chromophore, via a protonated Schiff base linkage to an amino group of lysine in the middle of the seventh transmembrane helix (TM7). Upon the absorption of light, microbial rhodopsins undergo light-induced photoisomerization of all-trans retinal into the 13-cis isomer, whereas the photoisomerization of 11-cis retinal to all-trans isomer occurs in the animal rhodopsins. While animal visual rhodopsins are activated by light to catalyze GDP/GTP exchange in the alpha subunit of the retinal G protein transducin (Gt), microbial rhodopsins do not activate G proteins, but instead can function as light-dependent ion pumps, cation channels, and sensors.
pfam13568, OMP_b-brl_2, Outer membrane protein beta-barrel domain. This domain is found in a wide range of outer membrane proteins. This domain assumes a membrane bound beta-barrel fold.
cd18109, SpoU-like_RNA-MTase, SAM-dependent RNA methylase related to SpoU-TrmH. RNA 2'-O ribose methyltransferase catalyzes the methyltransfer from S-adenosyl-L-methionine (AdoMet) to the 2'-OH group of ribose in tRNA or rRNA. It is part of the SpoU family of MTases, a subfamily of the SPOUT methyltransferase superfamily. The SPOUT methyltransferase superfamily is a large class of S-adenosyl-L-methionine (AdoMet or SAM)-dependent RNA MTases which are structurally characterized by a deep trefoil knot.
pfam04536, TPM_phosphatase, TPM domain. This family was first named TPM domain after its founding proteins: TLP18.3, Psb32 and MOLO-1. In Arabidopsis, this domain is called the thylakoid acid phosphatase -TAP - domain and has a Rossmann-like fold. In plants, the family resides in the thylakoid lumen attached to the outer membrane of the chloroplast/plastid. It is active in the photosystem II.
pfam15902, Sortilin-Vps10, Sortilin, neurotensin receptor 3,. Sortilin, also known in mammals as neurotensin receptor-3, is the archetypical member of a Vps10-domain (Vps10-D) that binds neurotrophic factors and neuropeptides. This domain constitutes the entire luminal part of Sortilin and is activated in the trans-Golgi network by enzymatic propeptide cleavage. The structure of the domain has been determined as a ten-bladed propeller, with up to 9 BNR or beta-hairpin turns in it. The mature receptor binds various ligands, including its own propeptide (Sort-pro), neurotensin, the pro-forms of nerve growth factor-beta (NGF)6 and brain-derived neurotrophic factor (BDNF)7, lipoprotein lipase (LpL), apo lipoprotein AV14 and the receptor-associated protein (RAP)1.
pfam08354, DUF1729, Domain of unknown function (DUF1729). This domain of unknown function is found in fatty acid synthase beta subunits together with the MaoC-like domain (pfam01575) and the Acyltransferase domain (pfam00698). The domain has been identified in fungi and bacteria.
pfam13589, HATPase_c_3, Histidine kinase-, DNA gyrase B-, and HSP90-like ATPase. This family represents, additionally, the structurally related ATPase domains of histidine kinase, DNA gyrase B and HSP90.
cd01087, Prolidase, Prolidase. E.C. 3.4.13.9. Also known as Xaa-Pro dipeptidase, X-Pro dipeptidase, proline dipeptidase., imidodipeptidase, peptidase D, gamma-peptidase. Catalyses hydrolysis of Xaa-Pro dipeptides; also acts on aminoacyl-hydroxyproline analogs. No action on Pro-Pro.
cd03498, SQR_TypeB_2_TM, Succinate:quinone oxidoreductase (SQR)-like Type B subfamily 2, transmembrane subunit; composed of proteins with similarity to the SQRs of Geobacter metallireducens and Corynebacterium glutamicum. SQR catalyzes the oxidation of succinate to fumarate coupled to the reduction of quinone to quinol. C. glutamicum SQR reduces low potential quinones such as menaquinone. SQR is also called succinate dehydrogenase (Sdh) or Complex II and is part of the citric acid cycle and the aerobic respiratory chain. SQR is composed of a flavoprotein catalytic subunit, an iron-sulfur protein and one or two hydrophobic transmembrane subunits. Members of this subfamily are classified as Type B as they contain one transmembrane subunit and two heme groups. The heme and quinone binding sites reside in the transmembrane subunit. The transmembrane subunit of members of this subfamily is also called Sdh cytochrome b558 subunit based on the Bacillus subtilis protein. The structural arrangement allows efficient electron transfer between the catalytic subunit, through iron-sulfur centers, and the transmembrane subunit containing the electron acceptor (quinone). The reversible reduction of quinone is an essential feature of respiration, allowing transfer of electrons between respiratory complexes. Proteins in this subfamily from G. metallireducens and G. sulfurreducens are bifunctional enzymes with SQR and QFR activities.
cd05346, SDR_c5, classical (c) SDR, subgroup 5. These proteins are members of the classical SDR family, with a canonical active site tetrad and a typical Gly-rich NAD-binding motif. 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.
pfam11294, DUF3095, Protein of unknown function (DUF3095). Some members in this bacterial family of proteins are annotated as adenylyl cyclase however this cannot be confirmed. Currently no function is known.
cd06251, M14_ASTE_ASPA-like, Peptidase M14 Succinylglutamate desuccinylase (ASTE)/aspartoacylase (ASPA)-like; uncharacterized subgroup. A functionally uncharacterized subgroup of the Succinylglutamate desuccinylase (ASTE)/aspartoacylase (ASPA) subfamily which is part of the M14 family of metallocarboxypeptidases. ASTE catalyzes the fifth and last step in arginine catabolism by the arginine succinyltransferase pathway, and aspartoacylase (ASPA, also known as aminoacylase 2, and ACY-2; EC:3.5.1.15) cleaves N-acetyl L-aspartic acid (NAA) into aspartate and acetate. NAA is abundant in the brain, and hydrolysis of NAA by ASPA may help maintain white matter. ASPA is an NAA scavenger in other tissues. Mutations in the gene encoding ASPA cause Canavan disease (CD), a fatal progressive neurodegenerative disorder involving dysmyelination and spongiform degeneration of white matter in children. This enzyme binds zinc which is necessary for activity. Measurement of elevated NAA levels in urine is used in the diagnosis of CD.
cd05272, TDH_SDR_e, L-threonine dehydrogenase, extended (e) SDRs. This subgroup contains members identified as L-threonine dehydrogenase (TDH). TDH catalyzes the zinc-dependent formation of 2-amino-3-ketobutyrate from L-threonine via NAD(H)-dependent oxidation. This group is distinct from TDHs that are members of the medium chain dehydrogenase/reductase family. This group has the NAD-binding motif and active site tetrad 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.
cd17557, REC_Rcp-like, phosphoacceptor receiver (REC) domain of cyanobacterial phytochrome response regulator Rcp and similar domains. This family is composed of response regulators (RRs) that are members of phytochrome-associated, light-sensing two-component signal transduction pathways such as Synechocystis sp. Rcp1, Tolypothrix sp. RcpA, and Agrobacterium tumefaciens bacteriophytochrome response regulator AtBRR. They are stand-alone RRs containing only a REC domain with no output/effector domain. The REC domain itself functions as an effector domain. Also included in this family us Methanosaeta harundinacea methanogenesis regulatory protein FilR2, also a stand-alone RR. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.
TIGR04122, hypothetical_protein, putative exonuclease, DNA ligase-associated. Members of this protein family frequently are found annotated as a putative exonuclease involved in mRNA processing. This protein is found, exclusively in bacteria, associated with three other proteins: an ATP-dependent DNA ligase, a helicase, and putative phosphoesterase.
cd00154, Rab, Ras-related in brain (Rab) family of small guanosine triphosphatases (GTPases). Rab GTPases form the largest family within the Ras superfamily. There are at least 60 Rab genes in the human genome, and a number of Rab GTPases are conserved from yeast to humans. Rab GTPases are small, monomeric proteins that function as molecular switches to regulate vesicle trafficking pathways. The different Rab GTPases are localized to the cytosolic face of specific intracellular membranes, where they regulate distinct steps in membrane traffic pathways. In the GTP-bound form, Rab GTPases recruit specific sets of effector proteins onto membranes. Through their effectors, Rab GTPases regulate vesicle formation, actin- and tubulin-dependent vesicle movement, and membrane fusion. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which mask C-terminal lipid binding and promote cytosolic localization. While most unicellular organisms possess 5-20 Rab members, several have been found to possess 60 or more Rabs; for many of these Rab isoforms, homologous proteins are not found in other organisms. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Since crystal structures often lack C-terminal residues, the lipid modification site is not available for annotation in many of the CDs in the hierarchy, but is included where possible.
TIGR04121, ATP-dependent_helicase, DEXH box helicase, DNA ligase-associated. Members of this protein family are DEAD/DEAH box helicases found associated with a bacterial ATP-dependent DNA ligase, part of a four-gene system that occurs in about 12 % of prokaryotic reference genomes. The actual motif in this family is DE[VILW]H.
TIGR02727, Uncharacterized_protein_YqgN, 5,10-methenyltetrahydrofolate synthetase. This enzyme, 5,10-methenyltetrahydrofolate synthetase, is also called 5-formyltetrahydrofolate cycloligase. Function of bacterial proteins in this family was inferred originally from the known activity of eukaryotic homologs. Recently, activity was shown explicitly for the member from Mycoplasma pneumonia. Members of this family from alpha- and gamma-proteobacteria, designated ygfA, are often found in an operon with 6S structural RNA, and show a similar pattern of high expression during stationary phase. The function may be to deplete folate to slow 1-carbon biosynthetic metabolism. [Central intermediary metabolism, One-carbon metabolism].
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')
