Figure 3. Schematic of interactions of the ligand with the dicarboxylate site residues.
Eight strong hydrogen bonds to the four carboxylate oxygens locate the ligand in the binding site and maintain a nonplanar conformation. In addition, His364 is positioned to interact with carboxylate oxygen O1 or an oxygen on C3 in the inhibitor or a reaction intermediate. The green dotted line shows the interaction of catalytic base Arg297 with C3 of the ligand, from which a proton is extracted during oxidation of succinate.