FIGURE 4.

Protein and ligand movements in the active site and back door regions during a 200-ps simulation based on the MD_dc·Mg·ADP·BeF_x protein conformation. The movements of ADP·P_i, protein, side chains, and the switch 1 backbone during the simulation are represented by gold arrows on the MD_dc·Mg·ADP·BeF_x structure (purple). Note that the BeF_x (left) and P_i (right) moieties are colored yellow for clarity. The average structure of the last 5 ps of the simulation is shown in green. As P_i moves away from ADP, it causes switch 1 to bulge into the 50-kDa cleft. Arg-238 and Lys-241 then swing into the γ-phosphate-binding site to coordinate P_i in its new position. Mg²⁺ is represented by a sphere in both structures.