title: The O2-responsive repressor PpsR2 but not PpsR1 transduces a light signal sensed by the BphP1 phytochrome in Rhodopseudomonas palustris CGA009.
abstract: Regulatory properties of bacteriophytochrome BphP1 were evaluated with respect to the photosynthesis gene transcription repressors PpsR1 and PpsR2 of Rhodopseudomonas palustris strain CGA009 in gene complementation, replacement and deletion experiments. The results indicate that 750 nm wavelength light activates BphP1 to antagonize repression of photosynthesis gene expression by PpsR2, but not PpsR1. It is suggested that an equilibrium exists between BphP1-active and -inactive conformations, with 750 nm light shifting the equilibrium to an active conformation, although a phenotypically detectable component of BphP1 is in the active conformation in the absence of illumination.
authors: Department of Microbiology & Immunology, University of British Columbia, Vancouver, BC, Canada.
authors: Stephan
authors: S
authors: Braatsch
authors: Jeanette A
authors: JA
authors: Johnson
authors: Kerstin
authors: K
authors: Noll
authors: J Thomas
authors: JT
authors: Beatty
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016368:Frameshift Mutation; D017353:Gene Deletion; D005816:Genetic Complementation Test; D008027:Light; D008958:Models, Molecular; D010100:Oxygen / Q000378:metabolism; D010834:Phytochrome / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012241:Rhodopseudomonas / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D010834:Phytochrome; D010100:Oxygen