Crystal Structure of Patatin-17 in Complex with Aged and Non-Aged Organophosphorus Compounds
Figure 2
Proposed catalytic mechanism for the active site of Pat17.
Asp215 (not shown) acts as a general base and activates the Ser77 nucleophile by abstracting its terminal hydrogen. The activated Ser77 (shown as –OH) attacks the acyl carbon of the substrate forming a tetrahedral intermediate whose negative charge is shielded by the oxyanion hole of Pat17 (not shown). Loss of R-OH yields an acyl-enzyme intermediate that is hydrolyzed rapidly (passing through another tetrahedral intermediate) to release the acyl moiety and regenerate the enzyme.