FIGURE 7.

Conformational changes of the MIDAS coordination sphere region upon the dissociation of PAII from CMG2. The equilibrated S_N structure is shown in gray. The equilibrated S_HE structure, where PAII becomes partially dissociated, is colored following the code defined in Fig. 1 b. Residues not belonging to the binding sites on CMG2 are dimmed. The S_N and S_HE structures were aligned using the coordinates of CMG2. The amino acids and water molecules W1 and W2 coordinating the MIDAS cation are shown in licorice representation. The coordination of water W1 by Asp-148^CMG2 is disturbed due to the dissociation of PAII in the S_HE structure. Shown in the inset are the profiles for the distance between MIDAS water W1 and two side-chain oxygens of Asp-148^CMG2 over the course of the equilibration of S_N and S_HE structures.