Fig. 3.

Core protein-induced annealing is mediated by the UAR and CS elements. (A) Mutations introduced in the UAR and CS elements of WNV. The initiator AUG is indicated in red. (B) Wild-type (wt) or mutant radioactively labelled RNA 1–164 was incubated with wild-type 3′FL-UTR RNA or with 3′ UTR RNAs containing mutations restoring the 5′–3′ UAR or 5′–3′ CS interactions. Protein-to-nucleotide molar ratios were 1/40 (lanes 2, 7, 12, 17, 21), 1/20 (lanes 3, 8, 13, 18, 23), 1/10 (lanes 4, 9, 14, 19, 24), and 1/5 (lanes 5, 10, 15, 20, 25). Lanes 1, 6, 11, 16, and 21 show RNA annealing in the absence of core protein. The percentage of 5′–3′ complex formation is indicated below the lanes. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of the article.)