Genetic and biochemical characterization of ISP6, a small mitochondrial outer membrane protein associated with the protein translocation complex.
To search genetically for additional components of the protein translocation apparatus of mitochondria, we have used low fidelity PCR mutagenesis to generate temperature-sensitive mutants in the outer membrane translocation pore component ISP42. A high copy number suppressor of temperature-sensitive isp42 has been isolated and sequenced. This novel gene, denoted ISP6, encodes a 61 amino acid integral membrane protein of the mitochondrial outer membrane, which is oriented with its amino-terminus facing the cytosol. Disruption of the ISP6 gene is without apparent effect in wild type yeast cells, but is lethal in temperature-sensitive isp42 mutants. Immunoprecipitation of the gene product, ISP42p, from mitochondria solubilized under mild conditions reveals a multi-protein complex containing ISP6p and ISP42p.
Kassenbrock
C K
CK
Department of Biochemistry and Biophysics, University of North Carolina, School of Medicine, Chapel Hill 27599-7260.
Cao
W
W
Douglas
M G
MG
D000595:Amino Acid Sequence; D001483:Base Sequence; D004271:DNA, Fungal; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D016153:Genes, Suppressor; D006358:Hot Temperature; D007425:Intracellular Membranes / Q000378:metabolism*; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins
D004271:DNA, Fungal; D005656:Fungal Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D029701:Saccharomyces cerevisiae Proteins; C082532:TOM6 protein, S cerevisiae; C066555:Tom40 protein, S cerevisiae