title: The light-harvesting complex II (B800-850) of Rhodobacter sulfidophilus: characterization and formation under different growth conditions.
abstract: The photosynthetic bacterium Rhodobacter sulfidophilus is able to grow chemotrophically and phototrophically at a broad range of light intensities. In contrast to other facultative phototrophs, R. sulfidophilus synthesizes reaction center and light-harvesting (LH) complexes, B870 (LHI) and B800-850 (LHII) even under full aerobic conditions in the dark. The content of bacteriochlorophyll (BChl) varied from 3.8 micrograms Bchl per mg cell protein when grown at high light intensity (20,000 lux) to 60 micrograms Bchl per mg cell protein when grown at low light intensities (6 lux). After a shift from high light to low light conditions, the size of the photosynthetic unit increased by a factor of 4. Chromatographic analysis of the LHII complex, isolated and purified from cells grown phototrophically (at high and low light intensities) and chemotrophically, could resolve only one type of alpha and one type of beta polypeptide in the purified complex, of which the N-terminal sequences have been determined.
authors.affiliation: Institut für Biologie II Mikrobiologie, Albert-Ludwigs Universität, Freiburg.
authors.forename: G E
authors.initials: GE
authors.lastname: Hagemann
authors.forename: N
authors.initials: N
authors.lastname: Gad'on
authors.forename: A
authors.initials: A
authors.lastname: Garcia
authors.forename: G
authors.initials: G
authors.lastname: Drews
authors.forename: M H
authors.initials: MH
authors.lastname: Tadros
mesh_terms: D000332:Aerobiosis; D000595:Amino Acid Sequence; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000032:analysis; D001429:Bacteriochlorophylls / Q000032:analysis; D002338:Carotenoids / Q000032:analysis; D003624:Darkness; D004307:Dose-Response Relationship, Radiation; D008027:Light; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins / Q000032:analysis; D008566:Membranes / Q000737:chemistry; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000096:biosynthesis / Q000737:chemistry*; D016992:Rhodobacter / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D017421:Sequence Analysis; D013053:Spectrophotometry
chemical_list: C085576:B870 light-harvesting protein complex, Bacteria; D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D002338:Carotenoids