Fig 4. Effect of the W501R substitution on the ability of RNA to stimulate HCV helicase-catalyzed ATP hydrolysis.

The increase in reaction rates (expressed as specific activities v/e (s^-1)) indicates greater stimulation of the ATP hydrolysis activity. The reactions were prepared containing25 mM MOPS (pH 6.5), 1.25 mM MgCl₂, 1 mM ATP, 1 nM, 0.05 mM DTT, 0.005 mg/mL BSA, 0.001% Tween20, and different concentrations of (A) poly (A) and (B) poly (U) RNA ranging from 0 nM to 10,000 nM.