Initial steps in the synthesis of functional tRNAs require 5'- and 3'-processing of precursor tRNAs (pre-tRNAs), which in yeast mitochondria are achieved by two endonucleases, RNase P and RNase Z. In this study, using a combination of detergent-free Blue Native Gel Electrophoresis, proteomics and in vitro testing of pre-tRNA maturation, we reveal the physical association of these plus other mitochondrial activities in a large, stable complex of 136 proteins. It contains a total of seven proteins involved in RNA processing including RNase P and RNase Z, five out of six subunits of the mitochondrial RNA degradosome, components of the fatty acid synthesis pathway, translation, metabolism and protein folding. At the RNA level, there are the small and large rRNA subunits and RNase P RNA. Surprisingly, this complex is absent in an oar1? deletion mutant of the type II fatty acid synthesis pathway, supporting a recently published functional link between pre-tRNA processing and the FAS II pathway--apparently by integration into a large complex as we demonstrate here. Finally, the question of mt-RNase P localization within mitochondria was investigated, by GFP-tracing of a known protein subunit (Rpm2p). We find that about equal fractions of RNase P are soluble versus membrane-attached.
|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||Annotation Extension||Reference|
|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||Assay||Construct||Conditions||Strain Background||Reference|