REPLACEMENT OF THE SACCHAROMYCES-CEREVISIAE RPR1 GENE WITH HETEROLOGOUS RNASE P-RNA GENES

Phylogenetic studies of yeast nuclear RNase P RNA genes have shown a s triking conservation of secondary structure for the Saccharomyces and Schizosaccharomyces RNase P RNAs, yet much of the primary sequence and many substructures vary among the RNAs examined. To investigate which sequences and structural features can be varied and still allow funct ion in a heterologous organism, RNase P genes from several yeast speci es were tested for the ability to substitute for the Saccharomyces cer evisiae RNA. The RNase P genes from Saccharomyces carlsbergensis and S accharomyces kluyveri could act as the sole source of RNase P RNA with in S.cerevisiae cells, whereas the genes from Saccharomyces globosus a nd Schizosaccharomyces pombe could not. Although heterologous RNase P RNAs were synthesized by the cells in all cases, the RNAs that complem ented tended to be processed from longer precursor transcripts into ma ture-sized RNase P RNA, while the RNAs that did not complement tended to accumulate as the longer precursor form. The results identified seq uences and structures in the RNA that are not essential for interactio n with species-specific proteins, processing or localization, and sugg ested other positions that may be candidates for such processes.