title: Ssr2998 of Synechocystis sp. PCC 6803 is involved in regulation of cyanobacterial electron transport and associated with the cytochrome b6f complex.
abstract: To analyze the function of a protein encoded by the open reading frame ssr2998 in Synechocystis sp. PCC 6803, the corresponding gene was disrupted, and the generated mutant strain was analyzed. Loss of the 7.2-kDa protein severely reduced the growth of Synechocystis, especially under high light conditions, and appeared to impair the function of the cytochrome b6 f complex. This resulted in slower electron donation to cytochrome f and photosystem 1 and, concomitantly, over-reduction of the plastoquinone pool, which in turn had an impact on the photosystem 1 to photosystem 2 stoichiometry and state transition. Furthermore, a 7.2-kDa protein, encoded by the open reading frame ssr2998, was co-isolated with the cytochrome b6 f complex from the cyanobacterium Synechocystis sp. PCC 6803. ssr2998 seems to be structurally and functionally associated with the cytochrome b6 f complex from Synechocystis, and the protein could be involved in regulation of electron transfer processes in Synechocystis sp. PCC 6803.
authors.affiliation: Biochemie der Pflanzen, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Volkmer
authors.forename: Dirk
authors.initials: D
authors.lastname: Schneider
authors.forename: Gábor
authors.initials: G
authors.lastname: Bernát
authors.forename: Helmut
authors.initials: H
authors.lastname: Kirchhoff
authors.forename: Stephan-Olav
authors.initials: SO
authors.lastname: Wenk
authors.forename: Matthias
authors.initials: M
authors.lastname: Rögner
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D045346:Cytochrome b6f Complex / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D004579:Electron Transport / Q000235:genetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D046939:Synechocystis / Q000201:enzymology* / Q000235:genetics* / Q000502:physiology
chemical_list: D045346:Cytochrome b6f Complex