Fig. 5. MMCoA binding to 12S. (A) Two molecules of MMCoA (purple space-filling) and one cadmium ion (yellow sphere) are at the interface between opposing monomers (yellow and blue). (B) MMCoA (bold) binding in the active site of 12S, with hydrogen bonding interactions (dashed lines) based on distances of 2.4–3.2 Å. (C) MMCoA carboxylate is stabilized by helices starting at residues 414 and 182.