FIG. 6.

After nicking, the relaxase remains tightly associated with its target DNA. The Mob(His₆)-DNA complexes were precipitated with KCl (0.25 M) in the presence of SDS (1%). The DNA recovered in the precipitate (P) and supernatant (S) was analyzed by agarose gel electrophoresis. Supercoiled DNA (1 μg of p2oriT DNA [lanes 1 to 6] or control DNA lacking the oriT [lanes 7 and 8]) was incubated in the presence (+) or absence (−) of Mob(His₆) protein (≅400 ng). The reaction was terminated by addition of EDTA (0.16 M) and SDS (1%) followed (+) or not followed (−) by incubation with proteinase K.