title: Structural and electron paramagnetic resonance (EPR) studies of mononuclear molybdenum enzymes from sulfate-reducing bacteria.
abstract: Molybdenum and tungsten are found in biological systems in a mononuclear form in the active site of a diverse group of enzymes that generally catalyze oxygen-atom-transfer reactions. The metal atom (Mo or W) is coordinated to one or two pyranopterin molecules and to a variable number of ligands such as oxygen (oxo, hydroxo, water, serine, aspartic acid), sulfur (cysteines), and selenium (selenocysteines) atoms. In addition, these proteins contain redox cofactors such as iron-sulfur clusters and heme groups. All of these metal cofactors are along an electron-transfer pathway that mediates the electron exchange between substrate and an external electron acceptor (for oxidative reactions) or donor (for reductive reactions). We describe in this Account a combination of structural and electronic paramagnetic resonance studies that were used to reveal distinct aspects of these enzymes.
authors.affiliation: REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Carlos D
authors.initials: CD
authors.lastname: Brondino
authors.forename: María G
authors.initials: MG
authors.lastname: Rivas
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Romão
authors.forename: José J G
authors.initials: JJ
authors.lastname: Moura
authors.forename: Isabel
authors.initials: I
authors.lastname: Moura
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000201:enzymology*; D001665:Binding Sites; D004578:Electron Spin Resonance Spectroscopy; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D004798:Enzymes / Q000737:chemistry* / Q000235:genetics; D005560:Formate Dehydrogenases / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008982:Molybdenum / Q000737:chemistry*; D013237:Stereoisomerism; D013431:Sulfates / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D004798:Enzymes; D013431:Sulfates; D008982:Molybdenum; D005560:Formate Dehydrogenases; D000445:Aldehyde Oxidoreductases