Fig. 3.

Importance of the structure rather than the sequence for packaging of S4. (a) Nucleotide sequences of ssRNA of mutants S4.15 and S4.16. Boxes indicate mutations. (b) RNAfold secondary RNA structure prediction of S4 mutants. Mutations are depicted in grey. (c) Upper panel: detection of S4 WT or mutant S4.15 and S4.16 RNAs in the reverse transcription packaging assay yielding an 874 bp product (white arrows). Controls for reverse transcription PCR: +ve, S4 of BTV-9 ssRNA; –ve, S4 of BTV-1 ssRNA. Middle and lower panels: as described in Fig. 1. For consistency, each experiment was performed twice.