7.6.2.9 evolution OpuF is a member of the Opu family of transporters. OpuF is not present in Bacillus subtilis but it is widely distributed in members of the large Bacillus genus. OpuF is a representative of a sub-group of ABC transporters in which the substrate-binding protein (SBP) is fused to the trans-locating subunit (TMD). The OpuF system is a representative of a growing sub-group of ABC transporters in which the substrate-scavenging function of the SBP and the membrane-embedded substrate TMD are fused into a single polypeptide chain 749673 7.6.2.9 evolution OpuF is a member of the Opu family of transporters. OpuF is widely distributed in members of the large Bacillus genus. OpuF is a representative of a sub-group of ABC transporters in which the substrate-binding protein (SBP) is fused to the trans-locating subunit (TMD). The OpuF system is a representative of a growing sub-group of ABC transporters in which the substrate-scavenging function of the SBP and the membrane-embedded substrate TMD are fused into a single polypeptide chain 749673 7.6.2.9 evolution the amino acid sequences of the components of Bacillus subtilis OpuB and OpuC ABC transporters are closely related to each other because the opuB and opuC operon are likely the result of a gene duplication event. The least conserved component of these two transporter systems are their substrate binding proteins (OpuBC and OpuCC, respectively) with a degree of amino acid sequence identity of 71% of the mature proteins. Gene opuAA (UniProt ID O32243) encodes the glycine betaine transport ATP-binding protein OpuAA (quaternary-amine-transporting ATPase) -, 750650 7.6.2.9 evolution the amino acid sequences of the components of Bacillus subtilis OpuB and OpuC ABC transporters are closely related to each other because the opuB and opuC operon are likely the result of a gene duplication event. The least conserved component of these two transporter systems are their substrate binding proteins (OpuBC and OpuCC, respectively) with a degree of amino acid sequence identity of 71% of the mature proteins. Gene opuAA (UniProt ID O32243) encodes the glycine betaine transport ATP-binding protein OpuAA (quaternary-amine-transporting ATPase). OpuA-type ABC transporters are identified by assessing the amino acid sequence relatedness with the OpuAC substrate-binding protein from Bacillus subtilis -, 750650 7.6.2.9 evolution the genome sequence of Bacillus infantis NRRL B-14911 predicts in addition to OpuA, the presence of several other types of osmostress protectant uptake systems (e.g. OpuF, OpuD, OpuE) -, 750650 7.6.2.9 evolution the structural genes encoding ABC-transporters OpuB and OpuC from Bacillus subtilis have most likely evolved through a duplication event but the two transporters are remarkably different in their substrate profile. The transporters are members of the type-I subfamily of ABC import systems. The substrate-binding protein-dependent ABC systems are all thought to be importers and probably originated from a common ancestor more than 3 billion years ago -, 751583 7.6.2.9 malfunction in-frame deletion mutation in the two putative ABC transporters and three putative BCCT family transporters associated with glycine betaine uptake cannot block cellular accumulation of betaine glycine in Vibrio anguillarum under cold stress, suggesting the redundant feature in Vibrio anguillarum betaine transporter system -, 751296 7.6.2.9 malfunction OpuB transporter lacking its solute receptor protein OpuBC is nonfunctional -, 751583 7.6.2.9 malfunction OpuC transporter lacking its solute receptor protein OpuCC is nonfunctional -, 751583 7.6.2.9 additional information an in silico model of the substrate-binding protein (SBP) domain of the transmembrane domain (TMD)-SPB hybrid protein OpuFB is established. It reveals the presence of an aromatic cage, a structural feature commonly present in ligand-binding sites of compatible solute importers 749673 7.6.2.9 physiological function five transporters for osmostress protectants (Opu) have been characterized in the systems for production of the compatible solutes proline and glycine betaine. Glycine betaine synthesis relies on the import of choline via the substrate-restricted OpuB system and the promiscuous OpuC transporter and its subsequent oxidation by the GbsAB enzymes. Transcription of the opuB and gbsAB operons is under control of the MarR-type regulator GbsR, which acts as an intracellular choline-responsive repressor. GbsR-/OpuAR-type proteins are an extended subgroup within the MarR-superfamily of transcriptional regulators and an additional type of substrate-inducible import system for osmostress protectants. The presence of either glycine betaine or proline betaine affords a substantial level of osmostress protection. Choline serves as the inducer for relief of GbsR-mediated repression of the Bacillus subtilis gbsAB and opuB operons -, 750650 7.6.2.9 physiological function five transporters for osmostress protectants (Opu) have been characterized in the systems for production of the compatible solutes proline and glycine betaine. Glycine betaine synthesis relies on the import of choline via the substrate-restricted OpuB system and the promiscuous OpuC transporter and its subsequent oxidation by the GbsAB enzymes. Transcription of the opuB and gbsAB operons is under control of the MarR-type regulator GbsR, which acts as an intracellular choline-responsive repressor. GbsR-/OpuAR-type proteins are an extended subgroup within the MarR-superfamily of transcriptional regulators and an additional type of substrate-inducible import system for osmostress protectants. The presence of either glycine betaine or proline betaine affords a substantial level of osmostress protection. Since the genome sequence of Bacillus infantis NRRL B-14911 lacks glycine betaine synthesis genes, it is readily understandable why choline is not osmostress protective, as this compound is not a compatible solute per se because its osmostress-relieving properties depend on its enzymatic conversion into glycine betaine -, 750650 7.6.2.9 physiological function five transporters for osmostress protectants (Opu) have been characterized in the systems for production of the compatible solutes proline and glycine betaine. Glycine betaine synthesis relies on the import of choline via the substrate-restricted OpuB system and the promiscuous OpuC transporter and its subsequent oxidation by the GbsAB enzymes. Transcriptional regulation of the Bacillus infantis opuA gene cluster via the GbsR-type regulator OpuAR, the Bacillus infantis GbsR protein is the OpuAR regulatory protein. GbsR-/OpuAR-type proteins are an extended subgroup within the MarR-superfamily of transcriptional regulators and an additional type of substrate-inducible import system for osmostress protectants. The presence of either glycine betaine or proline betaine affords a substantial level of osmostress protection. The major substrates (glycine betaine and proline betaine) of Bacillus infantis OpuA ABC importer also serve as inducers of OpuAR to relieve the DNA-binding activity of this repressor protein -, 750650 7.6.2.9 physiological function OpuF is another Bacillus compatible solute ABC transporter with a substrate-binding protein fused to the transmembrane domain. OpuF mediates the import of glycine betaine, proline betaine, homobetaine and the marine osmolyte dimethylsulfoniopropionate (DMSP). The high affinity import of compatible solutes from environmental sources is an important aspect of the cellular defense of many Bacteria and Archaea against the harmful effects of high external osmolarity. The accumulation of these osmostress protectants counteracts high osmolarity instigated water efflux, drop in turgor to non-physiological values, and an undue increase in molecular crowding of the cytoplasm, they thereby foster microbial growth under osmotically unfavorable conditions 749673 7.6.2.9 physiological function strains lacking opuABCD accumulate more trehalose under stress conditions than wild-type strains. OpuABCD mutant strains are more resistant to high-salt, low-pH and -hydrogen peroxide, conditions that mimic aspects of innate immunity, in a trehalose-dependent manner. In addition, OpuABCD mutant strains require the trehalose production genes to outcompete wild-type strains in mice and macrophages 720502 7.6.2.9 physiological function the ABC-transporters OpuB and OpuC from Bacillus subtilis function as osmoprotectant import systems. OpuB possesses narrow substrate specificity, while OpuC is promiscuous. Critical role of the binding protein OpuBC (UniProt ID Q45462) in setting the substrate specificity of ABC transporter. OpuABC, consisting of ATPase OpuBA and substrate-binding-protein OpuBC, acts as an osmoprotectant uptake system. A central role is played by the extra-cytoplasmic ligand-binding protein for the overall functioning of these importer systems. Osmostress protection under high-salinity growth conditions and import of various compatible solutes via the OpuB, OpuC, OpuB::OpuCC, and OpuC::OpuBC ABC transport systems, overview. GbsR-dependent regulation of opuB and gbsAB (glycine betaine biosynthetic gene cluster) expression -, 751583 7.6.2.9 physiological function the ABC-transporters OpuB and OpuC from Bacillus subtilis function as osmoprotectant import systems. OpuB possesses narrow substrate specificity, while OpuC is promiscuous. Critical role of the binding protein OpuCC (UniProt ID O32243) in setting the substrate specificity of ABC transporter. OpuACC, consisting of ATPase OpuCA and substrate-binding-protein OpuCC, acts as an osmoprotectant uptake system. A central role is played by the extra-cytoplasmic ligand-binding protein for the overall functioning of these importer systems. Osmostress protection under high-salinity growth conditions and import of various compatible solutes via the OpuB, OpuC, OpuB::OpuCC, and OpuC::OpuBC ABC transport systems, overview -, 751583 7.6.2.9 physiological function the amphipathic alpha-helix fused to the core of the transmembrane domain of the OpuABC subunit is located close to the membrane surface, where its hydrophobic face interacts with the transport protein rather than the membrane lipids. The amphipathic alpha-helix of OpuA is necessary for high activity of OpuA but is not critical for the biogenesis of the protein or the ionic regulation of transport 718937 7.6.2.9 physiological function the enzyme ontributes to the regulation of cell volume 734703 7.6.2.9 physiological function Vibrio anguillarum possesses a putative glycine betaine synthesis system, which is encoded by betABI and synthesizes glycine betaine from its precursor choline. Significant up-regulation of the bet gene at the transcriptional level is noted in log phase in response to cold-stress. The accumulation of betaine glycine is only appearing at low growth temperatures, suggesting that response regulation of both synthesis system and transporter system are cold-dependent. Two putative ABC transporters and three putative BCCT family transporters are associated with glycine betaine uptake. Glycine betaine serves as an effective cold stress protectant, thus the enzyme complex is involved in cold adaptation of Vibrio anguillarum via regulation of the glycine betaine level -, 751296 7.6.2.9 physiological function Vibrio anguillarum possesses a putative glycine betaine synthesis system, which is encoded by betABI and synthesizes glycine betaine from its precursor choline. Significant upregulation of the bet gene at the transcriptional level is noted in log phase in response to cold-stress. The accumulation of betaine glycine is only appearing at low growth temperatures, suggesting that response regulation of both synthesis system and transporter system are cold-dependent. Two putative ABC transporters and three putative BCCT family transporters are associated with glycine betaine uptake. Glycine betaine serves as an effective cold stress protectant, thus the enzyme complex is involved in cold adaptation of Vibrio anguillarum via regulation of the glycine betaine level -, 751296