Figure 4. SSB displacement from ssDNA by RecA_Ng and RecA_Ec.

The experiments were carried out as described in Materials and Methods. The order of addition and the source of the proteins are indicated in the figure. Control reactions (Δ and O) contained 3 µMnt M13mp18 cssDNA, and 4 µM RecA. After 10 minutes of incubation, at t = 0, 3 mM ATP and 0.5 µM SSB were added to initiate the reaction. In all other reactions, 0.5 µM SSB was incubated with 3 µMnt M13mp18 cssDNA and 3 mM ATP for 10 minutes until 4 µM RecA was added at t = 0.