FIG. 4.

The ESSV sequence acts to inhibit splicing in a heterologous context. (A) Schematic representation of minigene template constructs containing 5′ splice site D1 and 3′ splice site A3 (3). These constructs contain either ESS2, ESSV, or ESSVx. (B) ³²P-labeled RNA substrates HS1-ESS2, HS1-ESSV, and HS1-ESSVx were synthesized and RNA splicing was performed as described in Materials and Methods. Products of in vitro splicing of substrates were analyzed on denaturing polyacrylamide gels. The positions of the precursor and the spliced product are marked.