Figure 1.

(a) Six water molecules (spheres) observed in active-site cavity of the x-ray crystal structure of apo-P450cam and none in camphor-bound P450cam. Protein backbone is shown in ribbons, and the heme group and camphor molecule are shown as lines. (b) Number of water molecules found in the protein-active-site cavity of apo-P450cam versus the camphor-bound P450cam during MD simulation (100–300-ns time window). (c and d) Distribution of water molecules (points) in apo-P450cam (c) and camphor-bound P450cam (d) obtained from the MD trajectories up to 5 Å from the camphor-binding region: eight water clusters (number labels 1–8) (light gray/orange spheres) were identified surrounding the crystal water locations (dark gray/green spheres) in apo-P450cam and none in camphor-bound P450cam.