title: An unconventional copper protein required for cytochrome c oxidase respiratory function under extreme acidic conditions.
abstract: Very little is known about the processes used by acidophile organisms to preserve stability and function of respiratory pathways. Here, we reveal a potential strategy of these organisms for protecting and keeping functional key enzymes under extreme conditions. Using Acidithiobacillus ferrooxidans, we have identified a protein belonging to a new cupredoxin subfamily, AcoP, for "acidophile CcO partner," which is required for the cytochrome c oxidase (CcO) function. We show that it is a multifunctional copper protein with at least two roles as follows: (i) as a chaperone-like protein involved in the protection of the Cu(A) center of the CcO complex and (ii) as a linker between the periplasmic cytochrome c and the inner membrane cytochrome c oxidase. It could represent an interesting model for investigating the multifunctionality of proteins known to be crucial in pathways of energy metabolism.
authors.affiliation: Laboratoire de Bioénergétique et Ingénierie des Protéines, IMM-CNRS, 13402 Marseille Cedex 20, France.
authors.forename: Cindy
authors.initials: C
authors.lastname: Castelle
authors.forename: Marianne
authors.initials: M
authors.lastname: Ilbert
authors.forename: Pascale
authors.initials: P
authors.lastname: Infossi
authors.forename: Gisèle
authors.initials: G
authors.lastname: Leroy
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Giudici-Orticoni
mesh_terms: D042763:Acidithiobacillus / Q000201:enzymology*; D001400:Azurin / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D003576:Electron Transport Complex IV / Q000378:metabolism*; D004586:Electrophoresis; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry / Q000379:methods; D008667:Metalloproteins / Q000737:chemistry / Q000235:genetics; D008954:Models, Biological; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D011485:Protein Binding; D020349:Surface Plasmon Resonance; D013997:Time Factors
chemical_list: D008667:Metalloproteins; C050107:cupredoxin; D001400:Azurin; D003300:Copper; D003576:Electron Transport Complex IV