Fig. 5.

Final conformational changes in the latency transition involve twisting of s4A (the RCL) and movement of helix F. (A) Superimposed DRP structures of WT PAI-1 in the high-energy form immediately before completion of the latency transition (green) and in the final low-energy latent state (gray). Val341 and Val343, which undergo large rotamer changes, are shown in magenta for the high-energy form and in cyan sticks for the latent conformation. The expanded box highlights the relaxation of the twist in s4A (RCL) that accompanies the final stages of the latency transition. (B) As in A, but rotated to highlight the change in position of helix F. (C) Change in energy upon moving from the high-energy structure to the latent structure.