Testing Electrostatic Complementarity in Enzyme Catalysis: Hydrogen Bonding in the Ketosteroid Isomerase Oxyanion Hole
Figure 12
Structure of Equilenin (1OGX) and Phenolate Bound to pKSI D40N, Showing the Hydrogen Bonds from Tyr16 and Asp103 That Come from Above and Below the Plane of the Steroid
(A) For equilenin (PDB Code 1OGX [72]), average angles out of the plane of the steroid ring are 28° and 46°.
(B) For phenolate, the average angles are 15° and 47°.