Polymerase assays of WT D2 NS5, NS5 D4MT/D2POL, and NS5 D4MT K74I/D2POL proteins.
A, to evaluate the POL activity of recombinant NS5 proteins, the in vitro POL assay was performed using the D2 minigenome RNA as the template, D2 NS5, NS5 D4MT/D2POL, and the NS5 D4MT K74I/D2POL mutant, as described under “Experimental Procedures.” B, the signal intensities of the labeled RNAs synthesized in vitro were quantified by the PhosphorImager and plotted. Error bars, S.E.