Fig. 1

Active sites of metallo-β-lactamases. Klebsiella pneumoniae bi-Zn(II)-NDM-1 (B1, PDB 3spu, left), Serratia fonticola mono-Zn(II)-Sfh-I (B2, PDB 3sd9, center) and E. meningoseptica mono-Zn(II)-GOB-18 (B3, model based on PDB 5k0w, right). Zinc atoms are shown as grey spheres, and water molecules (W) are shown as small red spheres. Coordination bonds are indicated with dashed lines