A New Function of the Desulfovibrio vulgaris Hildenborough [Fe] Hydrogenase in the Protection against Oxidative Stress

• Published in: The Journal of biological chemistry Vol. 279; no. 3; pp. 1787 - 1793
• Main Authors: Fournier, Marjorie, Dermoun, Zorah, Durand, Marie-Claire, Dolla, Alain
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 16-01-2004; American Society for Biochemistry and Molecular Biology
• Subjects: chromic acid; Desulfovibrio vulgaris; Desulfovibrio vulgaris - enzymology; Hydrogenase - physiology; Iron-Sulfur Proteins - physiology; Oxidative Stress; Superoxide Dismutase - physiology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M307965200

Sulfate-reducing bacteria, like Desulfovibrio vulgaris Hildenborough, have developed a set of reactions allowing them to survive in oxic environments and even to reduce molecular oxygen to water. D. vulgaris contains a cytoplasmic superoxide reductase (SOR) and a periplasmic superoxide dismutase (SOD) involved in the elimination of superoxide anions. To assign the function of SOD, the periplasmic [Fe] hydrogenase activity was followed in both wild-type and sod deletant strains. This activity was lower in the strain lacking the SOD than in the wild-type when the cells were exposed to oxygen for a short time. The periplasmic SOD is thus involved in the protection of sensitive iron-sulfur-containing enzyme against superoxide-induced damages. Surprisingly, production of the periplasmic [Fe] hydrogenase was higher in the cells exposed to oxygen than in those kept in anaerobic conditions. A similar increase in the amount of [Fe] hydrogenase was observed when an increase in the redox potential was induced by addition of chromate. Viability of the strain lacking the gene encoding [Fe] hydrogenase after exposure to oxygen for 1 h was lower than that of the wild-type. These data reveal for the first time that production of the periplasmic [Fe] hydrogenase is up-regulated in response to an oxidative stress. A new function of the periplasmic [Fe] hydrogenase in the protective mechanisms of D. vulgaris Hildenborough toward an oxidative stress is proposed.