FIG 4.

PVA CP does not have a binding preference for the CP-encoding region of PVA RNA in vitro. The figure shows results of a representative EMSA using purified PVA CP incubated with RNAs corresponding to ∼800-nucleotide regions at opposite ends of the viral genome. The RNA on the left corresponds to the 5′-terminal P1-encoding region, and the RNA on the right to the 3′-terminal CP-encoding region. RNA transcripts were incubated with increasing molar ratios of PVA CP, as indicated by numerals. The theoretical RNA/CP molar ratio required for binding saturation is 1:160. The positions of cooperatively bound CP-RNA complexes (∼5 MDa) and free RNA are indicated by arrowheads. Note the lack of a pronounced difference in PVA CP binding between the two RNA transcripts.