Figure 7: Model for the role of RecN in the stimulation of the RecA strand invasion step of DNA DSB repair.

RecN interacts with RecA bound to a ssDNA region of one DNA molecule and with a target duplex DNA molecule. In vitro, this scenario leads to a relatively high rate of ATP hydrolysis by the RecN protein. One possible function of RecN ATP usage is the movement of the complex along or between potential target DNA molecules as part of a global search for homology. Alternatively, RecN protein may be affecting RecA–DNA filament dynamics and/or the topological state of the DNA, as discussed in the text.