Figure 3.

Active-site gorge of the original (A) and updated (B) structures of the complex of DmAChE with ZA (benzyltacrine). Residues of the catalytic triad (His480/Ser238), the oxyanion hole (Gly150/Gly151/Ala239), and key residues of the acyl-binding pocket (Trp271) and choline-binding pocket (Trp83), are represented as sticks, with carbons in white, nitrogens in blue, and oxygens in red. The bound sulfate, propionate, and ZA are shown as ball-and-stick models. H-bonds are shown as black dashes, with distances in Å. The meshes represent the 2 |Fo| – |Fc| map (1 σ blue) and the |Fo| – |Fc| difference map (3 σ green /−3 σ red).