FIGURE 3.

In vitro cleavage assays of RNase MRP on three different substrates. RNA substrates 3′-end labeled with ³²P were incubated with either NuMRP or MtMRP for 30 min at 37°C. The cleavage reactions were analyzed on a 6% polyacrylamide, 7 M urea gel as described in Materials and Methods. (A) Mitochondrial Ori5 substrate. (B) rRNA A3 substrate. (C) CLB2 mRNA substrate, (D) MtMRP and NuMRP were mixed together on the mitochondrial substrate at varying ratios.