FIG. 3.

Efficient polyadenylation of P7-driven transcripts at (pA)p requires a DSE that overlaps with the A2 3′ splice acceptor site. 293 cells were transfected with the P7JCap (diagrammed on the right, top) and the P7JCapA2CAA-based plasmids, which contain various mutations of the A2 3′ splice site, listed on the right. At the top right of the figure, the consensus PTB- and U2AF-binding sites and the conserved DSE are underlined. The G/U-rich DSE of AAV5 is boxed and overlaps with the A2 polypyrimidine tract (A2 PPT). The four potential cleavage sites of RNAs polyadenylated at (pA)p, determined previously (26), are indicated with arrows. RNA from uninfected cells generated no protection products.