Computational studies on the catalytic mechanism of phosphoketolase

By using density functional theory (DFT) method, the main formation mechanism of acetyl phosphate (AcP) and erythrose-4-phosphate (E4P) from fructose-6-phosphate (F6P) and Pi catalyzed by phosphoketolase (PK) has been studied on simplified models. The calculation results indicate that His64 is a better candidate of B1 catalyst, and His97 is the probable B2 catalyst in the dehydration process. His553 acts as a proton donor to protonate the carbonyl oxygen, and plays intermediary role in the Keto-Enol tautomerism process.