FIG 5.

Secondary structures of full-length (351-nt) V10-2 and V20-1 SC3 RREs. The secondary structures of V10-2 (A) and V20-1 (B) SC3 RREs were determined by CE-SHAPE. NMIA nucleotide reactivities are color coded and superimposed on the structures. The positions of the 8 nucleotides differing between the two RREs are represented by arrows. Mutations within the short 234-nt RRE are designated mut 1, mut 2, mut 3, and mut 4 and shown in green on the V20-1 RRE. Four additional mutations within stem SL-I are shown as green arrows without labels on the V20-1 RRE. The position of each of these changes is shown by black arrows on the V10-2 RRE.