title: Oxygen reduction in the strict anaerobe Desulfovibrio vulgaris Hildenborough: characterization of two membrane-bound oxygen reductases.
abstract: Although Desulfovibrio vulgaris Hildenborough (DvH) is a strictly anaerobic bacterium, it is able to consume oxygen in different cellular compartments, including extensive periplasmic O₂ reduction with hydrogen as electron donor. The genome of DvH revealed the presence of cydAB and cox genes, encoding a quinol oxidase bd and a cytochrome c oxidase, respectively. In the membranes of DvH, we detected both quinol oxygen reductase [inhibited by heptyl-hydroxyquinoline-N-oxide (HQNO)] and cytochrome c oxidase activities. Spectral and HPLC data for the membrane fraction revealed the presence of o-, b- and d-type haems, in addition to a majority of c-type haems, but no a-type haem, in agreement with carbon monoxide-binding analysis. The cytochrome c oxidase is thus of the cc(o/b)o₃ type, a type not previously described. The monohaem cytochrome c₅₅₃ is an electron donor to the cytochrome c oxidase; its encoding gene is located upstream of the cox operon and is 50-fold more transcribed than coxI encoding the cytochrome c oxidase subunit I. Even when DvH is grown under anaerobic conditions in lactate/sulfate medium, the two terminal oxidase-encoding genes are expressed. Furthermore, the quinol oxidase bd-encoding genes are more highly expressed than the cox genes. The cox operon exhibits an atypical genomic organization, with the gene coxII located downstream of coxIV. The occurrence of these membrane-bound oxygen reductases in other strictly anaerobic Deltaproteobacteria is discussed.
authors: Laboratoire Interactions et Modulateurs de Réponses, CNRS-UPR3243-IFR88, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors: O
authors: O
authors: Lamrabet
authors: Laboratoire Interactions et Modulateurs de Réponses, CNRS-UPR3243-IFR88, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors: L
authors: L
authors: Pieulle
authors: Laboratoire Interactions et Modulateurs de Réponses, CNRS-UPR3243-IFR88, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors: C
authors: C
authors: Aubert
authors: Laboratoire Interactions et Modulateurs de Réponses, CNRS-UPR3243-IFR88, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors: F
authors: F
authors: Mouhamar
authors: Sondes Moléculaires en Biologie, Laboratoire Chimie Provence, UMR 6264, CNRS-Universités Aix-Marseille, Faculté des Sciences de Saint-Jérôme, 13397 Marseille, France.
authors: P
authors: P
authors: Stocker
authors: Laboratoire Interactions et Modulateurs de Réponses, CNRS-UPR3243-IFR88, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors: A
authors: A
authors: Dolla
authors: Laboratoire Interactions et Modulateurs de Réponses, CNRS-UPR3243-IFR88, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors: G
authors: G
authors: Brasseur
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D016969:Desulfovibrio vulgaris / Q000201:enzymology* / Q000235:genetics; D004583:Electrons; D004789:Enzyme Activation; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D008565:Membrane Proteins / Q000378:metabolism*; D009876:Operon; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010802:Phylogeny
chemical_list: D008565:Membrane Proteins; D010088:Oxidoreductases; D010100:Oxygen