title: RegB/RegA, a highly conserved redox-responding global two-component regulatory system.
abstract: The Reg regulon from Rhodobacter capsulatus and Rhodobacter sphaeroides encodes proteins involved in numerous energy-generating and energy-utilizing processes such as photosynthesis, carbon fixation, nitrogen fixation, hydrogen utilization, aerobic and anaerobic respiration, denitrification, electron transport, and aerotaxis. The redox signal that is detected by the membrane-bound sensor kinase, RegB, appears to originate from the aerobic respiratory chain, given that mutations in cytochrome c oxidase result in constitutive RegB autophosphorylation. Regulation of RegB autophosphorylation also involves a redox-active cysteine that is present in the cytosolic region of RegB. Both phosphorylated and unphosphorylated forms of the cognate response regulator RegA are capable of activating or repressing a variety of genes in the regulon. Highly conserved homologues of RegB and RegA have been found in a wide number of photosynthetic and nonphotosynthetic bacteria, with evidence suggesting that RegB/RegA plays a fundamental role in the transcription of redox-regulated genes in many bacterial species.
authors.affiliation: Laboratoire de Biochimie et de Biophysique des Systèmes Intégrés (UMR 5092 CNRS-CEA-UJF), Grenoble, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Elsen
authors.forename: Lee R
authors.initials: LR
authors.lastname: Swem
authors.forename: Danielle L
authors.initials: DL
authors.lastname: Swem
authors.forename: Carl E
authors.initials: CE
authors.lastname: Bauer
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008954:Models, Biological; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010766:Phosphorylation; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D018085:Regulon; D016354:Rhodobacter capsulatus / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D011494:Protein Kinases