Catalytic Mechanism of Nonglycosidic C-N Bond Formation by the Pseudoglycosyltransferase Enzyme VldE.

ABSTRACT: The pseudoglycosyltransferase (PsGT) enzyme VldE is a homologue of the retaining glycosyltransferase (GT) trehalose 6-phosphate synthase (OtsA) that catalyzes a coupling reaction between two pseudo-sugar units, GDP-valienol and validamine 7-phosphate, to give a product with α,α-N-pseudo-glycosidic linkage. Despite its biological importance and unique catalytic function, the molecular bases for its substrate specificity and reaction mechanism are still obscure. Here, we report a comparative mechanistic study of VldE and OtsA using various engineered chimeric proteins and point mutants of the enzymes, X-ray crystallography, docking studies, and kinetic isotope effects. We found that the distinct substrate specificities between VldE and OtsA are most likely due to topological differenc

SUBMITTER: Tsunoda T 

PROVIDER: S-EPMC10732325 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature