Figure 13.3.

Detecting FtsK translocation activity on a DNA molecule by MT (A) FtsK activity events. The DNA molecule shortens as FtsK translocates and forms a DNA loop. The total change in DNA extension indicates the processivity of the enzyme, while the change in extension with time yields the translocation rate for each separate event; the average of these values would be measured in bulk experiments. (B) When negative supercoiling is introduced, one observes an initial increase in the DNA extension due to supercoil removal by FtsK as it twists and translocates on DNA to form a coiled DNA loop.