Conformational Itinerary of Sucrose During Hydrolysis by Retaining Amylosucrase.

ABSTRACT: By means of QM(DFT)/MM metadynamics we have unraveled the hydrolytic reaction mechanism of Neisseria polysaccharea amylosucrase (NpAS), a member of GH13 family. Our results provide an atomistic picture of the active site reorganization along the catalytic double-displacement reaction, clarifying whether the glycosyl-enzyme reaction intermediate features an α-glucosyl unit in an undistorted ⁴ C ₁ conformation, as inferred from structural studies, or a distorted ¹ S ₃-like conformation, as expected from mechanistic analysis of glycoside hydrolases (GHs). We show that, even though the first step of the reaction (glycosylation) results in a ⁴ C ₁ conformation, the α-glucosyl unit undergoes an e

SUBMITTER: Alonso-Gil S 

PROVIDER: S-EPMC6502901 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature