COX16 encodes a novel protein required for the assembly of cytochrome oxidase in Saccharomyces cerevisiae

J Biol Chem. 2003 Feb 7;278(6):3770-5. doi: 10.1074/jbc.M209893200. Epub 2002 Nov 22.

Abstract

We have characterized Cox16p, a new cytochrome oxidase (COX) assembly factor. This protein is encoded by COX16, corresponding to the previously uncharacterized open reading frame YJL003w of the yeast genome. COX16 was identified in studies of COX-deficient mutants previously assigned to complementation group G22 of a collection of yeast pet mutants. To determine its location, Cox16p was tagged with a Myc epitope at the C terminus. The fusion protein, when expressed from a low-copy plasmid, complements the mutant and is detected solely in mitochondria. Cox16p-myc is an integral component of the mitochondrial inner membrane, with its C terminus exposed to the intermembrane space. Cox16 homologues are found in both the human and murine genomes, although human COX16 does not complement the yeast mutant. Cox16p does not appear to be involved in maturation of subunit 2, copper recruitment, or heme A biosynthesis. Cox16p is thus a new protein in the growing family of eukaryotic COX assembly factors for which there are as yet no specific functions known. Like other recently described nuclear gene products involved in expression of cytochrome oxidase, COX16 is a candidate for screening in inherited human COX deficiencies.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cloning, Molecular
  • Electron Transport Complex IV / metabolism*
  • Humans
  • Membrane Proteins
  • Mice
  • Mitochondria / enzymology
  • Mitochondrial Proteins / chemistry
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism*
  • Molecular Sequence Data
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Sequence Homology, Amino Acid

Substances

  • COX16 protein, S cerevisiae
  • Membrane Proteins
  • Mitochondrial Proteins
  • Recombinant Fusion Proteins
  • Saccharomyces cerevisiae Proteins
  • Electron Transport Complex IV