Figure 4.

GES-2-ertapenem structure. (A) Stereoview of the final 2F_o– F_c electron density (blue mesh) contoured at 1 σ for some of the GES-2 residues (green) in the active site. The ertapenem molecule (magenta sticks) is shown in the initial F_o– F_c difference density (pink mesh) calculated following molecular replacement, contoured at 2.5 σ. The side chain of Asn170 is also shown in the same F_o– F_c electron density map since this residue was truncated to a glycine in the MR model used. The deacylating water molecule (W2) is also indicated as a red sphere. (B) Stereoview of the hydrogen bonding interactions between ertapenem (magenta sticks) and the GES-2 protein (green). (C) Superposition of the imipenem complexes of GES-1 and GES-5 onto the ertapenem-GES-2 complex (green). Ertapenem is shown as thick magenta sticks and imipenem as thin yellow and cyan sticks for GES-1 and GES-5, respectively. The GES-1 and GES-5 proteins are not shown for clarity.