In yeast, guide snoRNAs have been assigned to 51 of the 55 rRNA ribose methylation sites. LSU-Um2918 is one of the four remaining positions. This residue is highly conserved and located in the peptidyl transferase center of the ribosome. The equivalent position on the E. coli 23S rRNA is methylated by FtsJ/RrmJ which has three yeast homologs: Spb1, involved in biogenesis of LSU; Trm7, a tRNA methyltransferase; and Mrm2, a mitochondrial 21S rRNA methyltransferase. We demonstrate that a point mutation in the Ado-Met binding site of Spb1p affects cell growth but does not abolish methylation of U2918. When this mutation is combined with disruption of snR52 (a snoRNA C/D), cell growth is severely impaired and U2918 is no longer methylated. In vitro, Spb1p is able to methylate U2918 on 60S subunits. Our results reveal the importance of this methylation for which two mechanisms coexist: a site-specific methyltransferase (Spb1p) and a snoRNA-dependent mechanism.
|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|