Fig. 2.

Two types of free-energy maps for translocation process. (A) A map that describes the energetics of the translocation process of Fig. 1. The surface involves 2 effective coordinates; the protein structural changes (the Q axis) and the DNA translocation (the R axis). The indexes T₁ and T₂ designate the same T state but with a translated DNA. (B) A 2D map that describes an ineffective translocation. The surface is built in the same way as in Fig. 2A but now the motion from T to D does not involve a shift in the minimum. In this case, the system has an equal chance to move on paths A and C.