Fig. 3.

Branch migration of individual Holliday junctions. (A) Branch-migration trace obtained at 0.9 ± 0.2 μM RuvB and 0.6 pN. The contour length as a function of time exhibits sharp changes in branch-migration rates and pauses of much longer duration than traces obtained at 1.7 μM RuvB (Fig. 2). The rates are comparable in both cases. (B) Force-induced branch migration. RuvAB-induced branch migration is interrupted by fast runaway or force-induced migration episodes of the bead upward (arrows). Runaway migration episodes interrupt RuvAB-catalyzed branch migration either in the reverse or forward direction or after pauses.