title: Arsenite oxidase, an ancient bioenergetic enzyme.
abstract: Operons coding for the enzyme arsenite oxidase have been detected in the genomes from Archaea and Bacteria by Blast searches using the amino acid sequences of the respective enzyme characterized in two different beta-proteobacteria as templates. Sequence analyses show that in all these species, arsenite oxidase is transported over the cytoplasmic membrane via the tat system and most probably remains membrane attached by an N-terminal transmembrane helix of the Rieske subunit. The biochemical and biophysical data obtained for arsenite oxidase in the green filamentous bacterium Chloroflexus aurantiacus allow a structural model of the enzyme's membrane association to be proposed. Phylogenies for the two constituent subunits (i.e., the molybdopterin-containing and the Rieske subunit) of the heterodimeric enzyme and their respective homologs in DMSO-reductase, formate dehydrogenase, nitrate reductase, and the Rieske/cytb complexes were calculated from multiple sequence alignments. The obtained phylogenetic trees indicate an early origin of arsenite oxidase before the divergence of Archaea and Bacteria. Evolutionary implications of these phylogenies are discussed.
authors.affiliation: Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Biologie Structurale et Microbiologie, Marseille Cedex, France.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Lebrun
authors.forename: Myriam
authors.initials: M
authors.lastname: Brugna
authors.forename: Frauke
authors.initials: F
authors.lastname: Baymann
authors.forename: Daniel
authors.initials: D
authors.lastname: Muller
authors.forename: Didier
authors.initials: D
authors.lastname: Lièvremont
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Lett
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Nitschke
mesh_terms: D000595:Amino Acid Sequence; D001105:Archaea / Q000235:genetics*; D001419:Bacteria / Q000235:genetics*; D041861:Chloroflexus / Q000378:metabolism; D030541:Databases, Genetic; D014450:Electron Transport Complex III / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D016415:Sequence Alignment; D013057:Spectrum Analysis
chemical_list: D029968:Escherichia coli Proteins; D007506:Iron-Sulfur Proteins; D026901:Membrane Transport Proteins; C037989:Rieske iron-sulfur protein; C408585:twin-arginine translocase complex, E coli; D010088:Oxidoreductases; C078179:arsenite oxidase; D014450:Electron Transport Complex III