title: Evidence for the association of yeast mitochondrial ribosomes with Cox11p, a protein required for the Cu(B) site formation of cytochrome c oxidase.
abstract: Cytochrome c oxidase is the terminal enzyme of the mitochondrial (mt) respiratory chain. It contains copper ions, which are organized in two centres, Cu(A) and Cu(B). The Cu(A) site of subunit Cox2p is exposed to the mt intermembrane space, while the Cu(B) site of subunit Cox1p is buried in the inner mt membrane. Incorporation of copper into the two centres is crucial for the assembly and activity of the enzyme. Formation of the Cu(B) site is dependent on Cox11p, a copper-binding protein of the mt inner membrane. Here, we experimentally prove that Cox11p possesses a N(in)-C(out) topology, with the C-terminal copper-binding domain exposed in the mt intermembrane space. Furthermore, we provide evidence for the association of Cox11p with the mt translation machinery. We propose a model in which the Cu(B) site is co-translationally formed by a transient interaction between Cox11p and the nascent Cox1p in the intermembrane space.
authors.affiliation: Institut für Genetik, Technische Universität Dresden, 01062 Dresden, Germany. khalimon@mpi-cbg.de
authors.forename: Oleh
authors.initials: O
authors.lastname: Khalimonchuk
authors.forename: Kai
authors.initials: K
authors.lastname: Ostermann
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rödel
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D003300:Copper / Q000378:metabolism*; D017931:DNA Primers; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007425:Intracellular Membranes / Q000201:enzymology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C086106:COX11 protein, S cerevisiae; D017931:DNA Primers; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; D003300:Copper; D003576:Electron Transport Complex IV