rRNA molecules undergo extensive posttranscriptional modification, predominantly 2'-O-ribose methylation and pseudouridine formation, both of which are guided by the numerous small nucleolar RNAs in eukaryotes. Here, we describe an exception to this rule. The essential yeast nucleolar protein Spb1p is a site-specific rRNA methyltransferase modifying the universally conserved G2922 that is located within the A loop of the catalytic center of the ribosome. The equivalent position in bacteria is the docking site for aminoacyl-tRNA, and it is critical for translation. In sharp contrast to other 2'-O-methylriboses that are formed on the primary transcript, Gm2922 appears at a late processing stage, during the maturation of the 27S pre-rRNA. Thus, eukaryotes have maintained a site-specific enzyme to catalyze the methylation of a nucleotide that plays a crucial role in ribosome biogenesis and translation.
|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|