Figure 5.

Representation of the X-ray crystal structure of a complex between OMPDC and the intermediate analog 6-hydroxyuridine 5′-monophosphate (BMP, PDB entry 1DQX). Phosphodianion gripper loop is shaded blue, and the pyrimidine umbrella loop is shaded green. These loops are clamped over the substrate by the following network of hydrogen bonding interactions: (a) H-bonds between the Q215, Y217, and R235 side chains and the ligand phosphodianion; (b) H-bonds that link the −CH₂OH side chain of S154 to the amide side chain of Q215 and to the pyrimidine nitrogen. All distances are in Ångstroms.