title: Regulatory factors controlling photosynthetic reaction center and light-harvesting gene expression in Rhodobacter capsulatus.
abstract: Most species of photosynthetic bacteria synthesize their photosynthetic apparatus only under conditions of reduced oxygen tension. To a large extent, this phenomenon is dependent upon anaerobic induction of photosynthesis gene expression. Here we report an example of a regulatory gene, regA, that is involved in transactivating anaerobic expression of the photosynthetic apparatus. We show that RegA is itself responsible for differential induction of light-harvesting and reaction center gene expression relative to operons for photopigment biosynthesis. Surprisingly, strains disrupted for regA were found to retain normal photosynthetic growth capabilities under high light intensities. We further show that photosynthetic growth in the absence of transactivating structural gene expression is a consequence of the superoperonal organization of the photosynthetic gene cluster.
authors.affiliation: Department of Biology, Indiana University, Bloomington 47405.
authors.forename: M W
authors.initials: MW
authors.lastname: Sganga
authors.forename: C E
authors.initials: CE
authors.lastname: Bauer
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015964:Gene Expression Regulation, Bacterial; D015698:Genomic Library; D008027:Light; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D016354:Rhodobacter capsulatus / Q000235:genetics*; D016415:Sequence Alignment; D015534:Trans-Activators / Q000235:genetics*
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D015534:Trans-Activators