FIG. 6.

UV cross-linking to luciferase translocation mutants. UV cross-linking experiments were performed with proteins eluted from the wild-type (A) or mutant (B) apo-B RNA affinity columns. Proteins were incubated with ³²P-labeled apo-B RNA, wild-type luciferase RNA (Luc 1), or the luciferase translocation mutants Luc 3 and Luc 4, which contain 15 and 25 nt of the apo-B editing cassette, respectively. UV cross-linking was performed as described in Materials and Methods, and the samples were analyzed by SDS–7.5% PAGE. The position of the molecular size standards (in kilodaltons) are indicated on the right, and the position of the 65-kDa protein is indicated by an arrow.