The vast majority of nuclease activity in yeast mitochondria is due to a single polypeptide with an apparent molecular weight of 38,000. The enzyme is located in the mitochondrial inner membrane and requires non-ionic detergents for solubilization and activity. A combination of heparin-agarose and Cibacron blue-agarose chromatography was employed to purify the nuclease to approximately 90% homogeneity. The purified enzyme shows multiple activities: 1) RNase activity on single-stranded, but not double-stranded RNA, 2) endonuclease activity on single- and double-stranded DNA, and 3) a 5'-exonuclease activity on double-stranded DNA. Digestion products with DNA contain 5'-phosphorylated termini. Antibody raised against an analogous enzyme purified from Neurospora crassa (Chow, T. Y. K., and Fraser, M. (1983) J. Biol. Chem. 258, 12010-12018) inhibits and immunoprecipitates the yeast enzyme. This antibody inhibits 90-95% of all nuclease activity present in solubilized mitochondria, indicating that the purified nuclease accounts for the bulk of mitochondrial nucleolytic activity. Analysis of a mutant strain in which the gene for the nuclease has been disrupted supports this conclusion and shows that all detectable DNase activity and most nonspecific RNase activity in the mitochondria is due to this single enzyme.
|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|