PROCESSING OF PRE-RIBOSOMAL-RNA IN SACCHAROMYCES-CEREVISIAE

Post-transcriptional processing of precursor-ribosomal RNA comprises a complex pathway of endonucleolytic cleavages, exonucleolytic digestio n and covalent modifications. The general order of the various process ing steps is well conserved in eukaryotic cells, but the underlying me chanisms are largely unknown. Recent analysis of pre-rRNA processing, mainly in the yeast Saccharomyces cerevisiae, has significantly improv ed our understanding of this important cellular activity. Here we will review the data that have led to our current picture of yeast pre-rRN A processing.