Atomic isodensity surfaces
of the protonated catalytic base carboxylate
group from the MD simulations. Oxygen density is colored red and hydrogen
density white. In each case, the greatest 90% of the oxygen or hydrogen
density is shown as a transparent isosurface, and the greatest 50%
of the oxygen or hydrogen density is shown as an opaque isosurface.
The MD average structures of the heavy atoms of the steroid intermediate
(5-AND), the catalytic base Asp38(Glu), and the active site residues
Tyr14, Tyr55, and Asp99 are shown.