title: The Saccharomyces cerevisiae ADP/ATP carrier-iso 1 cytochrome c fusion protein: one-step purification and functional analysis in vitro.
abstract: Genetic expression versus plasmidic overexpression of a functional recombinant fusion protein combining the yeast Saccharomyces cerevisiae mitochondrial ADP/ATP carrier (Anc2p) and the iso-1-cytochrome c (Cyc1p) has been investigated, with the main aim of increasing the polar surface of the carrier to improve its crystallization properties. The gene encoding the his6-tagged fusion protein was expressed in yeast under the control of the regulatory sequences of ScANC2 or under the control of the strong yeast PMA1 promoter. In both cases, the chimeric carrier, Anc2-Cyc1(His6)p, was able to restore growth on a non-fermentable carbon source of a yeast strain devoid of functional ADP/ATP carrier, demonstrating its transport activity. Nevertheless, when the expression vector was used, the level of expression of Anc2-Cyc1(His6)p was no greater than that of the chimeric carrier obtained in yeast mitochondria after homologous recombination. Optimal conditions to extract and to purify Anc2-Cyc1(His6)p were determined. A series of detergents was screened for their ability to extract and to preserve in vitro the chimeric carrier. A rapid, single step purification of Anc2-Cyc1(His6)p was developed, using n-dodecyl-beta-d-maltoside (DoDM) as the best detergent to solubilize the chimeric protein. Carboxyatractyloside- (CATR-) and nucleotide-binding sites were preserved in the purified protein. Moreover, the Cyc1p moiety of Anc2-Cyc1(His6)p-CATR complex solubilized in DoDM was still able to interact in vitro with the cytochrome c oxidase (COX), with the same affinity as yeast Cyc1p. Improved production and purification of Anc2-Cyc1(His6)p-CATR complex opens up new possibilities for the use of this protein in crystallographic approaches to the yeast ADP/ATP carrier. Furthermore, Anc2-Cyc1(His6)p may be an useful molecular tool to investigate in vivo interactions between components of the respiratory chain complexes such as COX and the proteins implicated in ATP biogenesis, such as the ATP/ADP carrier.
authors.affiliation: Laboratoire de Biochimie et Biophysique des Systèmes Intégrés, Institut de Recherches en Technologies et Sciences du Vivant, UMR 5092 CNRS-CEA-Université Joseph Fourier (UJF), CEA-Grenoble, 17 Avenue des Martyrs, 38054 Grenoble Cedex 9, France.
authors.forename: Martial
authors.initials: M
authors.lastname: Rey
authors.forename: Xavier
authors.initials: X
authors.lastname: Brazzolotto
authors.forename: Benjamin
authors.initials: B
authors.lastname: Clémençon
authors.forename: Agathe
authors.initials: A
authors.lastname: Afchain
authors.forename: Gérard
authors.initials: G
authors.lastname: Brandolin
authors.forename: Ludovic
authors.initials: L
authors.lastname: Pelosi
mesh_terms: D001278:Atractyloside / Q000031:analogs & derivatives / Q000378:metabolism; D015153:Blotting, Western; D045304:Cytochromes c / Q000235:genetics / Q000378:metabolism*; D005822:Genetic Vectors / Q000235:genetics; D016681:Genome, Fungal; D008928:Mitochondria / Q000378:metabolism; D000226:Mitochondrial ADP, ATP Translocases / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D001278:Atractyloside; D045304:Cytochromes c; D000226:Mitochondrial ADP, ATP Translocases; C003853:carboxyatractyloside