FIG. 3.

Deletion of stem-loops SL1 and SL2 from the branched double-hairpin structure increases genotype III amber/W RNA editing in a nonreplicating RNA. (A) Schematic of the branched double-hairpin RNA structure. The amber/W site is indicated by an asterisk; SL1 and SL2 denote stem-loops 1 and 2. CS denotes sequences com-plementary to sequences in the immediate vicinity of the amber/W site; base pairing between these sets of sequences is essential for amber/W editing (3). Sequences deleted in mutants M24 (nucleotides 1022 to 1090) and M25 (nucleotides 539 to 612) are shown boxed by dashed lines. (B) Huh-7 cells were transfected with the nonreplicating genotype III antigenomic RNA expression construct pHDV-III-NR containing either wild-type sequences or the indicated mutations. Editing was analyzed as in Fig. 1. The values shown are the average of editing in three independent samples from one experiment and are representative of other experiments that gave similar results. Standard deviations are indicated by vertical lines.