FIG. 5.

Effects of different nucleotides on degradation of mitochondrial polyadenylated RNA. Mitochondrial vesicles were labeled with [α-³²P]CTP for 8.5 min and chased for 65 min in transcription buffer containing 2 mM unlabeled CTP plus the indicated nucleotide at a concentration of 2 mM. At the times indicated, incorporation of [α-³²P]CTP into poly(A)⁺ RNA was determined. (A) ATP and GTP; (B) UMP and UDP; (C) uridine and dTTP. As a reference, the same degradation curves of poly(A)⁺ RNAs chased in the absence and presence of 2 mM UTP from Fig. 4 are shown on each graph.