Biochemical and functional analysis of the YME1 gene product, an ATP and zinc-dependent mitochondrial protease from S. cerevisiae.
Inactivation of YME1 in yeast causes several distinct phenotypes: an increased rate of DNA escape from mitochondria, temperature-sensitive growth on nonfermentable carbon sources, extremely slow growth when mitochondrial DNA is completely absent from the cell, and altered morphology of the mitochondrial compartment. The protein encoded by YME1, Yme1p, contains two highly conserved sequence elements, one implicated in the binding and hydrolysis of ATP, and the second characteristic of active site residues found in neutral, zinc-dependent proteases. Both the putative ATPase and zinc-dependent protease elements are necessary for the function of Yme1p as genes having mutations in critical residues of either of these motifs are unable to suppress any of the phenotypes exhibited by yme1 deletion strains. Yme1p co-fractionates with proteins associated with the mitochondrial inner membrane, is tightly associated with this membrane, and is oriented with the bulk of the protein facing the matrix. Unassembled subunit II of cytochrome oxidase is stabilized in yme1 yeast strains. The data support a model in which Yme1p is an ATP and zinc-dependent protease associated with the matrix side of the inner mitochondrial membrane. Subunit II of cytochrome oxidase, when not assembled into a higher order complex, is a likely substrate of Yme1p.
Weber
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Department of Molecular Biology, University of Wyoming, Laramie 82071-3944, USA.
Hanekamp
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Thorsness
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D049069:ATP-Dependent Proteases; D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001483:Base Sequence; D004271:DNA, Fungal; D003576:Electron Transport Complex IV / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015032:Zinc / Q000378:metabolism*
D004271:DNA, Fungal; D006360:Heat-Shock Proteins; D029701:Saccharomyces cerevisiae Proteins; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV; D049069:ATP-Dependent Proteases; D012697:Serine Endopeptidases; C082702:YME1 protein, S cerevisiae; D000251:Adenosine Triphosphatases; D015032:Zinc