Fig. 6.

ATPase and helicase activity of nsp13-K289A. (A) wild-type (WT) nsp13 or mutant nsp13-K289A proteins were incubated with ATP in reaction buffer at 37℃ for 10 min, then the ATPase activity was measured. (B) 0.3 μM of dsDNA substrates and 2 μM of WT nsp13 or nsp13-K289A proteins were mixed for 30 min at room temperature, then loaded into 6 % nondenaturing PAGE at 4℃ and run for 60 min. BSA was set as the negative control. (C) 0.3 μM of 5′-overhang dsDNA and 20 nM of WT nsp13 or nsp13-K289A proteins were mixed in reaction buffer at 30℃ for 10 min, then loaded on 8 % nondenaturing PAGE at 4℃ and run for 45 min.