title: petR, located upstream of the fbcFBC operon encoding the cytochrome bc1 complex, is homologous to bacterial response regulators and necessary for photosynthetic and respiratory growth of Rhodobacter capsulatus.
abstract: Interposon mutagenesis of a region upstream of the petABC(fbcFBC) operon, encoding the ubiquinol: cytochrome c2 oxidoreductase (bc1 complex) of the photosynthetic bacterium Rhodobacter capsulatus revealed the presence of two genes, petP and petR. DNA nucleotide sequence determination of this region indicated that petP and petR are transcribed in the same direction as the petABC(fbcFBC) operon, and are translationally coupled. A silent insertion located in the interoperonal region separating petPR and the petABC(fbcFBC) genes indicated that these clusters have separate promoters. The deduced amino acid sequence of the putative petR gene product is homologous to various bacterial response regulators, especially to those of the OmpR subgroup. Moreover, it was found that PetR mutants are unable to grow on rich or minimal media by either photosynthesis or respiration, demonstrating that these gene products are essential for growth of R. capsulatus.
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia 19104-6019.
authors.forename: M K
authors.initials: MK
authors.lastname: Tokito
authors.forename: F
authors.initials: F
authors.lastname: Daldal
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004269:DNA, Bacterial / Q000032:analysis; D014450:Electron Transport Complex III / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics* / Q000502:physiology; D005809:Genes, Regulator / Q000235:genetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009876:Operon / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D010788:Photosynthesis / Q000235:genetics; D016354:Rhodobacter capsulatus / Q000235:genetics / Q000254:growth & development*; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D014450:Electron Transport Complex III