Detoxification of hydrogen peroxide and expression of catalase genes in Rhodobacter.
The two related facultatively photosynthetic bacteria Rhodobacter sphaeroides and Rhodobacter capsulatus show different sensitivities against peroxide stress. R. sphaeroides is able to tolerate higher concentrations of H2O2 and exhibits higher catalase activity than R. capsulatus. The katE gene of R. sphaeroides and the katG gene of R. capsulatus are strongly induced by H2O2. This induction depends on the presence of the OxyR protein, which is able to bind to the promoter regions of these genes. In addition to katE R. sphaeroides harbours the katC gene, which shows no significant response to H2O2 but is induced in stationary phase.
Institut für Mikrobiologie und Molekularbiologie, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.
Tanja
T
Zeller
Gabriele
G
Klug
D002374:Catalase / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006861:Hydrogen Peroxide / Q000378:metabolism*; D018384:Oxidative Stress; D016992:Rhodobacter / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
D012808:Sigma Factor; D014157:Transcription Factors; D006861:Hydrogen Peroxide; D002374:Catalase