Mechanism of phosphatidylinositol-specific phospholipase C: a unified view of the mechanism of catalysis

The mechanism of phosphatidylinositol-specific phospholipase C from Bacillus thuringiensis was investigated. Site-directed mutagenesis was used to examine the functional and structural roles of His-32, His-82, Asp -274 and Asp-33. Results show that His-32 acts as a general base to abstract the proton from 2-OH and induces the attack of the deprotonated 2-oxygen on the atom of the phosphorus. His-82, on the other hand, functions as the general acid with support from Asp-33.