The proteolytic processing of the mitochondrially encoded subunit II of cytochrome oxidase is prevented by the yeast mutation ts2858. We report that the mutant is, in addition, temperature sensitive for the processing of cytochrome b2, a protein encoded by nuclear DNA. Thus the same mutation affects the removal of pre-sequences from a mitochondrially encoded inner membrane protein and from an imported soluble protein located in the intermembrane space. The mutation blocks the second processing step of cytochrome b2. The cytochrome b2 intermediate accumulates in the mutant at 36 degrees C and assumes its enzyme activity. At 23 degrees C the conversion to the mature protein is considerably slower than in wild-type cells. The similarity of the cleavage sites Asn-Asp and Asn-Glu of the precursors for cytochrome oxidase subunit II and cytochrome b2, respectively, suggests a sequence-specific recognition by one protease or a factor activating a protease. On the other hand maturation of cytochrome c peroxidase, another enzyme of the intermembrane space, is not affected by the pet ts2858 mutation.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|