A collection of yeast strains surviving with mutant 5S RNA has been constructed. The mutant strains presented alterations of the nucleolar structure, with less granular component, and a delocalization of the 25S rRNA throughout the nucleoplasm. The 5S RNA mutations affected helix I and resulted in decreased amounts of stable 5S RNA and of the ribosomal 60S subunits. The shortage of 60S subunits was due to a specific defect in the processing of the 27SB precursor RNA that gives rise to the mature 25S and 5.8S rRNA. The processing rate of the 27SB pre-rRNA was specifically delayed, whereas the 27SA and 20S pre-rRNA were processed at a normal rate. The defect was partially corrected by increasing the amount of mutant 5S RNA. We propose that the 5S RNA is recruited by the pre-60S particle and that its recruitment is necessary for the efficient processing of the 27SB RNA precursor. Such a mechanism could ensure that all newly formed mature 60S subunits contain stoichiometric amounts of the three rRNA components.
|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|