title: Mineral respiration under extreme acidic conditions: from a supramolecular organization to a molecular adaptation in Acidithiobacillus ferrooxidans.
abstract: Acidithiobacillus ferrooxidans is an acidophilic chemolithoautotrophic Gram-negative bacterium that can derive energy from the oxidation of ferrous iron at pH 2 using oxygen as electron acceptor. The study of this bacterium has economic and fundamental biological interest because of its use in the industrial extraction of copper and uranium from ores. For this reason, its respiratory chain has been analysed in detail in recent years. Studies have shown the presence of a functional supercomplex that spans the outer and the inner membranes and allows a direct electron transfer from the extracellular Fe2+ ions to the inner membrane cytochrome c oxidase. Iron induces the expression of two operons encoding proteins implicated in this complex as well as in the regeneration of the reducing power. Most of these are metalloproteins that have been characterized biochemically, structurally and biophysically. For some of them, the molecular basis of their adaptation to the periplasmic acidic environment has been described. Modifications in the metal surroundings have been highlighted for cytochrome c and rusticyanin, whereas, for the cytochrome c oxidase, an additional partner that maintains its stability and activity has been demonstrated recently.
authors.affiliation: Unité de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée-CNRS, Aix-Marseille University, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Magali
authors.initials: M
authors.lastname: Roger
authors.forename: Cindy
authors.initials: C
authors.lastname: Castelle
authors.forename: Marianne
authors.initials: M
authors.lastname: Guiral
authors.forename: Pascale
authors.initials: P
authors.lastname: Infossi
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Lojou
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Giudici-Orticoni
authors.forename: Marianne
authors.initials: M
authors.lastname: Ilbert
mesh_terms: D042763:Acidithiobacillus / Q000378:metabolism*; D000220:Adaptation, Biological; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism / Q000502:physiology; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism / Q000502:physiology; D005296:Ferrous Compounds / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D033903:Periplasmic Proteins / Q000378:metabolism / Q000502:physiology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D005296:Ferrous Compounds; D033903:Periplasmic Proteins; D003576:Electron Transport Complex IV