Figure 1.

(A) Ball-and-stick model of a dioxane molecule and a water molecule binding at a subtilisin crystal contact. Carbon, oxygen, and nitrogen are depicted in white, light gray, and dark gray, respectively. |F_o–F_c|φ_calc map, omitting solvent molecules, is shown in white at the 3σ contour. (B) The solvent molecules are displayed as in A; shown in white is the F_c theoretical electron density map for the water and dioxane molecules.