title: Shortcut of the photosynthetic electron transfer in a mutant lacking the reaction center-bound cytochrome subunit by gene disruption in a purple bacterium, Rubrivivax gelatinosus.
abstract: A mutant lacking the reaction center-bound cytochrome subunit was constructed in a purple photosynthetic bacterium, Rubrivivax gelatinosus IL144, by inactivation of the cytochrome gene. Photosynthetic growth of the C244 mutant strain occurred at approximately half the rate of the wild-type strain. Although mutagenesis resulted in a greatly reduced amount of membrane-bound cytochromes c, illumination induced cyclic electron transfer and the generation of membrane potential in the mutant as observed in the wild-type strain. These findings are consistent with previous observations that the cytochrome subunit is absent in the reaction center complex in some species of purple bacteria and that the biochemical removal of the subunit did not significantly affect the in vitro electron transfer from the soluble cytochrome c to the photosynthetic reaction center. These results suggest that the cytochrome subunit in purple bacteria is not essential for photosynthetic electron transfer and growth, even in those species generally containing the subunit.
authors.affiliation: Department of Biology, Tokyo Metropolitan University, Japan.
authors.forename: K V
authors.initials: KV
authors.lastname: Nagashima
authors.forename: K
authors.initials: K
authors.lastname: Shimada
authors.forename: K
authors.initials: K
authors.lastname: Matsuura
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D001483:Base Sequence; D015139:Blotting, Southern; D002455:Cell Division; D003574:Cytochrome c Group / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D004579:Electron Transport; D017353:Gene Deletion; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D012244:Rhodospirillaceae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013053:Spectrophotometry; D014634:Valinomycin / Q000494:pharmacology
chemical_list: D003574:Cytochrome c Group; D017931:DNA Primers; D045322:Photosynthetic Reaction Center Complex Proteins; D014634:Valinomycin; D001205:Ascorbic Acid