Fig. 4.

Active site of AMP-PCP bound to LpxK. (A) Active site stereo view reveals AMP-PCP bound in the “closed” enzyme conformation between the C-terminal domain and β–linker. Waters (red spheres) and putative hydrogen bonds (dashed lines) are indicated. Simulated annealing omit electron density for AMP-PCP (mesh) was calculated with coefficients F_o – F_c, contoured at 4 σ. (B) Overlay of AMP-PCP (cyan) and ADP-Mg²⁺ (PDB: 4EHY) (green) LpxK structures. Side chains and hydrogen bonds (dashed lines) are colored accordingly. The Mg²⁺ ion of the ADP/Mg²⁺ structure is bound at the same site as the γ–phosphate of AMP-PCP.