Dark Aerobic Growth Conditions Induce the Synthesis of a High Midpoint Potential Cytochrome c8 in the Photosynthetic Bacterium Rubrivivax gelatinosus

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• 作者：Laure Menin ; Makoto Yoshida ; Michel Jaquinod ; Kenji V. P. Nagashima ; Katsumi Matsuura ; Pierre Parot ; and André ; Vermé ; glio
• 刊名：Biochemistry
• 出版年：1999
• 出版时间：November 16, 1999
• 年：1999
• 卷：38
• 期：46
• 页码：15238 - 15244
• 全文大小：97K
• 年卷期：v.38,no.46(November 16, 1999)
• ISSN：1520-4995

文摘

In several strains of the photosynthetic bacterium Rubrivivax gelatinosus, the synthesis of ahigh midpoint potential cytochrome is enhanced 4-6-fold in dark aerobically grown cells compared withanaerobic photosynthetic growth. This observation explains the conflicting reports in the literatureconcerning the cytochrome c content for this species. This cytochrome was isolated and characterized indetail from Rubrivivax gelatinosus strain IL144. The redox midpoint potential of this cytochrome is +300mV at pH 7. Its molecular mass, 9470 kDa, and its amino acid sequence, deduced from gene sequencing,support its placement in the cytochrome c₈ family. The ratio of this cytochrome to reaction center liesbetween 0.8 and 1 for cells of Rvi. gelatinosus grown under dark aerobic conditions. Analysis of light-induced absorption changes shows that this high-potential cytochrome c₈ can act in vivo as efficient electrondonor to the photooxidized high-potential heme of the Rvi. gelatinosus reaction center.