FIG 4.
Characterization of interviral recombinants generated between TBSV repRNA and NoV RNA1 in yeast. (A) RT-PCR analysis of the occurrence of (−)recRNA recombinants in wt and pmr1Δ yeast strains. TBSV repRNA, p33 and p92pol replication proteins, and NoV RNA1 were coexpressed in yeast from plasmids, as shown. See further details in the legend of Fig. 1B. (B) Schematic representation of the most frequent interviral (−)RNA recombinant containing the NoV RNA1 sequence at the 3′ region and the TBSV sequence at the 5′ region, as shown. The number of isolations of different hot spot regions in the interviral recombinants is shown. The actual sequences of the recRNAs are presented in Table S6 in the supplemental material. (C) Proposed tombusvirus replicase-driven template-switching model of the formation of interviral (−)recRNAs between TBSV repRNA and NoV RNA1.