Fig. 4.

Sequence analysis of RNA produced from mutant templates. 5′ RACE analysis of the RNA generated from the 1U-C, 1U-A, and Δ1U mutants (A, B, and C, respectively). In each case, i shows agarose gel electrophoresis of the 5′ RACE product generated from RNA from cells transfected with plasmid encoding the relevant mutant minireplicon and either lacking or containing the L polymerase plasmid or lacking MVA-T7, as indicated; ii shows sequence analysis of the input minireplicon plasmid DNA isolated from the transfected cells, and iii shows the corresponding sequence trace derived from the bulk 5′ RACE product (tailed with dGTP). The sequence traces are presented as template sense DNA; TrC sequence is underlined, with position 1 relative to the WT template indicated by an arrow. Sequencing of 5′ RACE reactions tailed with dCTP and of clonal isolates (Fig. S4) showed that the G peak at position 1 in iii is a sequencing artifact.