Model structure of CMY-185. (a) Overall structure of CMY-185. The substitution residues are shown as CPK representations coloured in magenta. To clarify the substrate-binding site, the ceftazidime molecule is shown as a white ball-and-stick representation. (b, c) Close-up views of the model structures of the CMY-185 complex with ceftazidime (b) or avibactam (c). (d, e) Close-up views of the crystal structures of the AmpC^Ent385 complex with ceftazidime (d, PDB accession number 6LC9) or avibactam (e, PDB accession number 6LC8). Hydrogen bonds are represented as orange dashed lines.