Figure 4.

Rpp2 is required for processing of both ptRNA and 5.8S rRNA, and for the steady-state levels of both RNase P and RNase MRP RNAs. (A) Growth curve of wild-type (WT, VS301D) and Rpp2-depleted (GAL∷rpp2, VS301A) cells after a switch from galactose- to glucose-containing medium at t = 0. Total RNA was extracted from exponentially growing cells (OD₆₀₀ < 0.5) at t = 0, 5, 8, 12, 26, 30, and 35 hr after a switch from galactose- to glucose-containing medium. (B) Total RNA isolated at the specified times from GAL∷rpp2 (VS301A) and wild-type (VS301D) cells was separated on an 8% polyacrylamide/7 M urea gel and visualized by staining with ethidium bromide. The relative migration positions of 5.8S (L), 5.8S (S), 5S rRNAs, and precursor and mature tRNAs are indicated. (C) The gel from B was transferred to a positively charged nylon membrane by electroblotting and hybridized with ³²P-labeled complementary DNA probes to RNase P RNA (RPR1), RNase MRP RNA (NME1) (see ref. 14), and γ-³²P-labeled oligonucleotide complementary to snRNA 190 (see Materials and Methods). pRPR1 is the putative precursor of RPR1 RNA that has extra sequences at both termini (8).