Figure 2.

Differential binding affinity of hnRNP H affects its ability to stimulate 3′-end processing of the SVL and IVA₂ polyadenylation signals. SVL (A) and IVA₂ (B) RNAs were incubated with the indicated amount of recombinant hnRNP H protein. Heparin-resistant RNA–protein complexes were analyzed on 5% native acrylamide gels. The arrows on the right of each panel indicate the positions of hnRNP H–RNA complexes. (C) The indicated amounts of hnRNP H protein were added to in vitro cleavage reactions containing either the SVL or IVA₂ polyadenylation signal RNAs. Reaction products were analyzed on a 5% acrylamide gel containing 7 M urea. hnRNP H at 15 ng had a 4.2-fold greater effect on the SVL versus the IVA₂ polyadenylation signal. hnRNP H at 100 ng stimulated both signals to a similar extent (6.8-fold).