FIG. 6.

The EMCV IRES targets cleavage to 3′-flanking SRPα sequences. (A) Uncapped, unlabeled SRPα and SRPα StuI IRES RNAs were combined with RRLs containing vhs (lanes marked vhs) and with control RRL (lanes marked RC), and samples were withdrawn at the indicated times (in minutes). RNAs were then extracted and analyzed by primer extension, using a 5′-labeled oligonucleotide that anneals to residues 1841 to 1865 of SRPα RNA (and residues 2424 to 2448 of the SRPα StuI IRES transcript). Numbered arrows indicate the positions of novel 5′ ends resulting from vhs-induced RNA cleavage. (B) Diagram showing the nucleotide sequence at the 3′ boundary of the IRES in SRPα StuI IRES RNA. Numbered arrows correspond to those in panel A and indicate the locations of the vhs-induced cleavage sites.