TIGR01386, Probable_sensor_protein_PcoS, heavy metal sensor kinase. Members of this family contain a sensor histidine kinase domain (pfam00512) and a domain found in bacterial signal proteins (pfam00672). This group is separated phylogenetically from related proteins with similar architecture and contains a number of proteins associated with heavy metal resistance efflux systems for copper, silver, cadmium, and/or zinc.
cd08576, GDPD_like_SMaseD_PLD, Glycerophosphodiester phosphodiesterase-like domain of spider venom sphingomyelinases D, bacterial phospholipase D, and similar proteins. This subfamily corresponds to the glycerophosphodiester phosphodiesterase-like domain (GDPD-like) present in sphingomyelinases D (SMases D) (sphingomyelin phosphodiesterase D, EC 3.1.4.4) from spider venom, the Corynebacterium pseudotuberculosis Phospholipase D (PLD)-like protein from pathogenic bacteria, and the Ajellomyces capsulatus H143 PLD-like protein from ascomycetes. Spider SMases D and bacterial PLD proteins catalyze the Mg2+-dependent hydrolysis of sphingomyelin producing choline and ceramide 1-phosphate (C1P), which possess a number of biological functions, such as regulating cell proliferation and apoptosis, participating in inflammatory responses, and playing a key role in phagocytosis. In the presence of Mg2+, SMases D can function as lysophospholipase D and hydrolyze lysophosphatidylcholine (LPC) to choline and lysophosphatidic acid (LPA), which is a multifunctional phospholipid involved in platelet aggregation, endothelial hyperpermeability, and pro-inflammatory responses. Loxosceles spider venoms' SMases D are the principal toxins responsible for dermonecrosis and complement dependent haemolysis induced by spider venom. Due to amino acid substitutions at the entrance to the active-site pocket, some members lack activity. The typical GDPD domain consists of a TIM barrel and a small insertion domain named as the GDPD-insertion (GDPD-I) domain, which is specific for GDPD proteins. Although proteins in this family contain a non-typical GDPD domain which lacks the GDPD-I, their catalytic mechanisms are based on Mg2+-dependent acid-base reactions similar to GDPD proteins. They might be divergent members of the GDPD family. Moreover, this family does not belong to phospholipase D (PLD) superfamily, since it lacks the conserved HKD sequence motif that characterizes the catalytic center of the PLD superfamily. It belongs to the superfamily of PLC-like phosphodiesterases.
COG0745, OmpR, Response regulators consisting of a CheY-like receiver domain and a winged-helix DNA-binding domain [Signal transduction mechanisms / Transcription].
pfam05401, NodS, Nodulation protein S (NodS). This family consists of nodulation S (NodS) proteins. The products of the rhizobial nodulation genes are involved in the biosynthesis of lipochitin oligosaccharides (LCOs), which are host-specific signal molecules required for nodule formation. NodS is an S-adenosyl-L-methionine (SAM)-dependent methyltransferase involved in N methylation of LCOs. NodS uses N-deacetylated chitooligosaccharides, the products of the NodBC proteins, as its methyl acceptors.
TIGR00476, selenide_water_dikinase, selenium donor protein. In prokaryotes, the incorporation of selenocysteine as the 21st amino acid, encoded by TGA, requires several elements: SelC is the tRNA itself, SelD acts as a donor of reduced selenium, SelA modifies a serine residue on SelC into selenocysteine, and SelB is a selenocysteine-specific translation elongation factor. 3-prime or 5-prime non-coding elements of mRNA have been found as probable structures for directing selenocysteine incorporation. This model describes SelD, known as selenophosphate synthetase, selenium donor protein, and selenide,water dikinase. SelD provides reduced selenium for the selenium transferase SelA. This protein itself contains selenocysteine in many species; any sequence scoring well but not aligning to the beginning of the model is likely to have a selenocysteine residue incorrectly interpreted as a stop codon upstream of the given sequence. The SelD protein also provides selenophosphate for the enzyme tRNA 2-selenouridine synthase, which catalyzes a tRNA base modification. It also contributes to selenium incorporation by selenium-dependent molybdenum hydroxylases (SDMH), in genomes with the marker TIGR03309. All genomes with SelD should make selenocysteine, selenouridine, SDMH, or some combination.
pfam16113, ECH_2, Enoyl-CoA hydratase/isomerase. This family contains a diverse set of enzymes including: enoyl-CoA hydratase, napthoate synthase, carnitate racemase, 3-hydroxybutyryl-CoA dehydratase and dodecanoyl-CoA delta-isomerase. This family differs from pfam00378 in the structure of it's C-terminus.
TIGR01553, Formate_dehydrogenase_major_subunit, formate dehydrogenase-N alpha subunit. This model describes a subset of formate dehydrogenase alpha chains found mainly in proteobacteria but also in Aquifex. The alpha chain contains domains for molybdopterin dinucleotide binding and molybdopterin oxidoreductase (pfam01568 and pfam00384, respectively). The holo-enzyme also contains beta and gamma subunits of 32 and 20 kDa. The enzyme catalyzes the oxidation of formate (produced from pyruvate during anaerobic growth) to carbon dioxide with the concomitant release of two electrons and two protons. The electrons are utilized mainly in the nitrate respiration by nitrate reductase. In E. coli and Salmonella, there are two forms of the formate dehydrogenase, one induced by nitrate which is strictly anaerobic (fdn), and one incuced during the transition from aerobic to anaerobic growth (fdo). This subunit is one of only three proteins in E. coli which contain selenocysteine. This model is well-defined, with a large, unpopulated trusted/noise gap. [Energy metabolism, Anaerobic, Energy metabolism, Electron transport].
cd10560, FDH-O_like, beta subunit of formate dehydrogenase O (FDH-O) and similar proteins. This subfamily includes beta subunit of formate dehydrogenase family O (FDH-O), which is highly homologous to formate dehydrogenase N (FDH-N), a member of the DMSO reductase family. In E. coli three formate dehydrogenases are synthesized that are capable of oxidizing formate; Fdh-H, couples formate disproportionation to hydrogen and CO2, and is part of the cytoplasmically oriented formate hydrogenlyase complex, while FDH-N and FDH-O indicate their respective induction after growth with nitrate and oxygen. Little is known about FDH-O, although it shows formate oxidase activity during aerobic growth and is also synthesized during nitrate respiration, similar to FDH-N.
pfam03916, NrfD, Polysulphide reductase, NrfD. NrfD is an integral transmembrane protein with loops in both the periplasm and the cytoplasm. NrfD is thought to participate in the transfer of electrons, from the quinone pool into the terminal components of the Nrf pathway.
pfam16980, CitMHS_2, Putative citrate transport. CitMHS is a family of putative citrate transporters, belonging to the Na+/H+ antiporter NhaD-like permease superfamily.
pfam09707, Cas_Cas2CT1978, CRISPR-associated protein (Cas_Cas2CT1978). This entry represents a minor branch of the Cas2 family of CRISPR-associated protein which are found in IPR003799. Cas proteins are found adjacent to a characteristic short, palindromic repeat cluster termed CRISPR, a probable mobile DNA element.
cd09756, Cas5_I-E, CRISPR/Cas system-associated RAMP superfamily protein Cas5. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and associated Cas proteins comprise a system for heritable host defense by prokaryotic cells against phage and other foreign DNA; Cas5 is a RAMP superfamily protein; Subunit of the Cascade complex.
pfam09485, CRISPR_Cse2, CRISPR-associated protein Cse2 (CRISPR_cse2). Clusters of short DNA repeats with non-homologous spacers, which are found at regular intervals in the genomes of phylogenetically distinct prokaryotic species, comprise a family with recognisable features. This family is known as CRISPR (short for Clustered, Regularly Interspaced Short Palindromic Repeats). A number of protein families appear only in association with these repeats and are designated Cas (CRISPR-Associated) proteins. This family of proteins, represented by CT1973 from Chlorobaculum tepidum, is encoded by genes found in the CRISPR/Cas subtype Ecoli regions of many bacteria (most of which are mesophiles), and not in Archaea. It is designated Cse2.
pfam09344, Cas_CT1975, CT1975-like protein. CRISPR is a term for Clustered, Regularly Interspaced Short Palidromic Repeats. A number of protein families appear only in association with these repeats and are designated Cas (CRISPR-Associated) proteins. This family is represented by CT1975 of Chlorobium tepidum.
TIGR03089, conserved_hypothetical_protein, TIGR03089 family protein. This protein family is found, so far, only in the Actinobacteria (Streptomyces, Mycobacterium, Corynebacterium, Nocardia, Propionibacterium, etc.) and never more than one to a genome. Members show twilight-level sequence similarity to family of AMP-binding enzymes described by pfam00501.
pfam10756, bPH_6, Bacterial PH domain. This domain has a bacterial type PH domain structure. This domain was previously known as DUF2581. This family is conserved in the Actinomycetales. Although several members are annotated as RbiX homologs, RbiX being a putative regulator of riboflavin biosynthesis, the function could not be confirmed.
TIGR03638, cas1_ECOLI, CRISPR-associated endonuclease Cas1, subtype I-E/ECOLI. The CRISPR-associated protein Cas1 is virtually universal to CRISPR systems. CRISPR, an acronym for Clustered Regularly Interspaced Short Palindromic Repeats, is prokaryotic immunity system for foreign DNA, mostly from phage. CRISPR systems belong to different subtypes, distinguished by both nature of the repeats, the makeup of the cohort of associated Cas proteins, and by molecular phylogeny within the more universal Cas proteins such as this one. This model is of type EXCEPTION and provides more specific information than the EQUIVALOG model TIGR00287. It describes the Cas1 protein particular to the ECOLI subtype of CRISPR/Cas system.
pfam18395, Cas3_C, Cas3 C-terminal domain. This is the C-temrinal domain of Cas3 proteins. The C-terminal domain (CTD) is shown to completely wrap ssDNA inside the helicase. Deletion of the CTD (aa 819-924) reduced CRISPR interference. It is suggested that the CTD regulates the N-terminal HD nuclease activity by functioning as a substrate filter.
pfam09481, CRISPR_Cse1, CRISPR-associated protein Cse1 (CRISPR_cse1). Clusters of short DNA repeats with non-homologous spacers, which are found at regular intervals in the genomes of phylogenetically distinct prokaryotic species, comprise a family with recognisable features. This family is known as CRISPR (short for Clustered, Regularly Interspaced Short Palindromic Repeats). A number of protein families appear only in association with these repeats and are designated Cas (CRISPR-Associated) proteins. This entry, represented by CT1972 from Chlorobaculum tepidum, is found in the CRISPR/Cas subtype Ecoli regions of many bacteria (most of which are mesophiles), and not in Archaea. It is designated Cse1.
pfam18019, HD_6, HD domain. This HD domain is found at the N-terminus of Cas3 enzymes fused to a helicase domain. This domain is sometimes found as a separate protein. It acts as a nuclease that cleaves ssDNA.
TIGR02669, stage_II_sporulation_protein_D, SpoIID/LytB domain. This model describes a domain found typically in two or three proteins per genome in Cyanobacteria and Firmicutes, and sporadically in other genomes. One member is SpoIID of Bacillus subtilis. Another in B. subtilis is the C-terminal half of LytB, encoded immediately upstream of an amidase, the autolysin LytC, to which its N-terminus is homologous. Gene neighborhoods are not well conserved for members of this family, as many, such as SpoIID, are monocistronic. One early modelling-based study suggests a DNA-binding role for SpoIID, but the function of this domain is unknown. [Unknown function, General].
cd12954, MMP_TTHA0227_like_1, Minimal MMP-like domain found in a group of hypothetical proteins from alphaproteobacteria and actinobacteria. The subfamily includes some uncharacterized bacterial proteins which show high sequence similarity with Thermus thermophilus hypothetical protein TTHA0227. However, they do not contain the conserved HExxH (x could be any amino acid) motif. They may not have any zinc metallo-peptidase activity.
