Fig. 6.

A qualitative free-energy landscape for the coupling between chemical coordinate and conformational coordinate. The y axis represents the reaction coordinate for the nucleophilic step in the 2W mechanism. The x axis represents the conformational change going from inactive EF-G to active EF-G (EF-G′). The figure was generated as described in Supporting Information, section S4. For simplicity, we did not attempt to determine the conformational free energy and set the corresponding change to zero.