Fig. 3.

Mutational evidence that unwinding by CMG using ATPγS is not due to a contaminant of ATP. (A) Reactions were performed using the N30-bp forked DNA and ATP without preincubation using either wt CMG (first seven lanes) or CMG that carries a mutation in the Walker A box (CMG^K-A) (second set of lanes). Use of twice the concentration of the CMG^K-A mutant is shown in the third set of seven lanes, and use of equal amounts of the CMG^K-A mutant plus the wt CMG is shown in the last seven lanes. (B) The reactions are the same as explained in A, except for use of 0.3 M ATPγS in place of 0.3 M ATP.