Fig. (3) NS5A activates the NS5B replication reaction with the 3’ UTR SL (+). A. Radiolabeled 3’UTR SL (+)template. B. NS5A titration during preincubation with NS5B (0.3 µM) prior to starting the replication reaction: 10 nM NS5A, lane 2; 1 nM NS5A, lane 3; 100 pM NS5A, lane 4; 10 pM NS5A, lane 5; 1 pM NS5A, lane 6; 0.1 pM NS5A, lane 7. Lane 8 shows the reaction with NS5B alone. Arrow indicates the expected RNA product. C. Quantitation of stimulation of NS5B by varying amounts of NS5A. Results are the average of 2 independent experiments.