Fig. 2.

Active site structures of resting state HGDO_Pp (A) and its complex with the substrate HG (B). Electron density maps in the vicinity of the active site are shown as blue mesh for the 2F_obs − F_calc map and as green mesh for the F_obs − F_calc simulated-annealing omit map. The weighted 2F_obs − F_calc maps of A and B are contoured at 1.2 σ. The F_obs − F_calc omit maps in A and B are contoured at 3.5 σ and were generated after removing modeled atoms from the active site structure. Possible hydrogen–bonding interactions are shown as blue dashed lines with distances given in angstroms. Iron and solvent molecules are shown as purple and red spheres, respectively.