title: Desulfoferrodoxin of Clostridium acetobutylicum functions as a superoxide reductase.
abstract: Desulfoferrodoxin (cac2450) of Clostridium acetobutylicum was purified after overexpression in E. coli. In an in vitro assay the enzyme exhibited superoxide reductase activity with rubredoxin (cac2778) of C. acetobutylicum as the proximal electron donor. Rubredoxin was reduced by ferredoxin:NADP(+) reductase from spinach and NADPH. The superoxide anions, generated from dissolved oxygen using Xanthine and Xanthine oxidase, were reduced to hydrogen peroxide. Thus, we assume that desulfoferrodoxin is the key factor in the superoxide reductase dependent part of an alternative pathway for detoxification of reactive oxygen species in this obligate anaerobic bacterium.
authors.affiliation: University of Rostock, Institute of Biological Sciences, Division of Microbiology, Albert-Einstein-Strasse 3, D-18051, Rostock, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Riebe
authors.forename: Ralf-Jörg
authors.initials: RJ
authors.lastname: Fischer
authors.forename: Hubert
authors.initials: H
authors.lastname: Bahl
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D046969:Clostridium acetobutylicum / Q000201:enzymology*; D045304:Cytochromes c / Q000378:metabolism; D005288:Ferredoxins / Q000302:isolation & purification / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012416:Rubredoxins / Q000302:isolation & purification; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D005288:Ferredoxins; D017382:Reactive Oxygen Species; D012416:Rubredoxins; C066602:desulfoferrodoxin; D013481:Superoxides; D045304:Cytochromes c; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; C121849:superoxide reductase; D013482:Superoxide Dismutase