Free energy of the DFG flip transition.

<p>Free energy surfaces of Abl, Src (adapted from Ref. [<a href="" target="_blank">29</a>]), and Abl drug-resistant mutants projected on the distances between DFG Asp<sub>404</sub> and Lys<sub>295</sub> (CV1) and DFG Phe<sub>405</sub> and Ile<sub>293</sub> (Leu<sub>137</sub> in Src) (CV2). The free energy minima corresponding to DFG-in conformations are labeled “IN”, while “OUT” correspond to DFG-out conformations. The contour lines are drawn every 1 kcal/mol.</p>