Fig. 1.

BMV RNA3 variants used in the in vitro and whole-plant experiments. Wt RNA3 is shown on the top with the ClaI restriction site indicated. An intermediate SF-23 construct carries a sequence corresponding to the BamHI marker site, whereas B3-33del carries a 33-aa deletion in the 3a ORF. JS-14 and JS-21 are sgRNA3a constructs carrying 3′ polyA tails of 14 and 21 A residues, respectively, plus RNA sequences corresponding to BamHI and PstI marker sites, whereas JS-0 does not carry a 3′ polyA tail. sg3a-384 is a (+) strand RNA primer corresponding to a middle region of the RNA3 sequence. Thin lines mark non-coding regions, whereas shaded rectangles represent ORFs for the 3a movement and coat (CP) proteins. The positions of marker sites are indicated by small vertical bars. To construct RW (−) RNA3, a portion of (−) RNA3 between nts 1 and 1914 (the nucleotide positions correspond to those in wt genomic (+) RNA3) was fused immediately downstream of the (+) RNA3 promoter (nts 1915–2111). The sequences complementary to the 3a and CP ORFs are shown as thick lines with the corresponding nucleotide positions below (for more details, see Wierzchoslawski and Bujarski, 2006).