Figure 4.

Structure of metal-bound (purple) and metal-free (yellow) cADO-L194A in complex with 1 (PDB ID 4PGI). (A) Overlay of the two conformations of cADO; metal-bound form in purple; metal-free form in yellow, in which helix 5 is partially unfolded between the residues 154 and 165. (B) Details of the active site geometry for the metal-bound form. (C) Detail of the substrate entry channel showing conformational changes in L194 and F130 with the structure of the stearate-bound form of cADO superimposed for comparison. (D) Details of the active site geometry in the metal-free form in which the substrate intrudes into the metal-binding site. The carboxylate group of E157 is disordered in both conformations and has therefore not been modeled in the structure.