title: Study of the spin-spin interactions between the metal centers of Desulfovibrio gigas aldehyde oxidoreductase: identification of the reducible sites of the [2Fe-2S]1+,2+ clusters.
abstract: The aldehyde oxidoreductase from Desulfovibrio gigas belongs to the family of molybdenum hydroxylases. Besides a molybdenum cofactor which constitutes their active site, these enzymes contain two [2Fe-2S](2+,1+) clusters which are believed to transfer the electrons provided by the substrate to an acceptor which is either a FAD group or an electron-transferring protein. When the three metal centers of D. gigas AOR are simultaneously paramagnetic, splittings due to intercenter spin-spin interactions are visible when the EPR spectra are recorded at low temperatures. By studying quantitatively these interactions with a model based on the X-ray crystal structure, which takes into consideration the interactions between the magnetic moments carried by all the metal sites of the system, it is possible to determine the location of the reducible sites of the [2Fe-2S] clusters. When combined with the electron-transfer pathways proposed on the basis of the X-ray crystal structure, the results provide a detailed description of the electron-transfer system of D. gigas AOR.
authors.affiliation: Laboratoire de Bioénergétique et Ingénierie des Protéines, UPR 9036 CNRS and Université de Provence, 31 Chemin Joseph Aiguier, 13402 Marseille, France.
authors.forename: Claude
authors.initials: C
authors.lastname: More
authors.forename: Marcel
authors.initials: M
authors.lastname: Asso
authors.forename: Guy
authors.initials: G
authors.lastname: Roger
authors.forename: Bruno
authors.initials: B
authors.lastname: Guigliarelli
authors.forename: Jorge
authors.initials: J
authors.lastname: Caldeira
authors.forename: José
authors.initials: J
authors.lastname: Moura
authors.forename: Patrick
authors.initials: P
authors.lastname: Bertrand
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000737:chemistry* / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D003198:Computer Simulation; D045286:Desulfovibrio gigas / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000378:metabolism*; D008892:Milk / Q000201:enzymology; D010084:Oxidation-Reduction; D014969:Xanthine Oxidase / Q000737:chemistry / Q000378:metabolism
chemical_list: D007506:Iron-Sulfur Proteins; D005182:Flavin-Adenine Dinucleotide; D014969:Xanthine Oxidase; D000445:Aldehyde Oxidoreductases