Human O-GlcNAcase Uses a Preactivated Boat-skew Substrate Conformation for Catalysis. Evidence from X-ray Crystallography and QM/MM Metadynamics

CALVELO, Martín, MALES, Alexandra, ALTEEN, Matthew G, WILLEMS, Lianne I, VOCADLO, David J, DAVIES, Gideon J and ROVIRA, Carme (2023). Human O-GlcNAcase Uses a Preactivated Boat-skew Substrate Conformation for Catalysis. Evidence from X-ray Crystallography and QM/MM Metadynamics. ACS Catalysis, 13 (20), 13672-13678. [Article]

Documents
33470:640023
[thumbnail of Males-HumanO-GlcNAcase(VoR).pdf]
Preview
PDF
Males-HumanO-GlcNAcase(VoR).pdf - Published Version
Available under License Creative Commons Attribution.

Download (4MB) | Preview
Abstract
Human O-linked β-N-acetylglucosaminidase (hOGA) is one of the two enzymes involved in nuclear and cytoplasmic protein O-GlcNAcylation, an essential post-translational modification. The enzyme catalyzes the hydrolysis of the GlcNAc-O-(Ser/Thr) glycosidic bonds via anchimeric assistance through the 2-acetamido group of the GlcNAc sugar. However, the conformational itinerary of the GlcNAc ring during catalysis remains unclear. Here we report the crystal structure of wild type hOGA in complex with a nonhydrolyzable glycopeptide substrate and elucidate the full enzyme catalytic mechanism using QM/MM metadynamics. We show that the enzyme can bind the substrate in either a chair- or a boat-like conformation, but only the latter is catalytically competent, leading to the reaction products via 1,4B/1S3 → [4E]‡ → 4C1 and 4C1 → [4E]‡ → 1,4B/1S3 conformational itineraries for the first and second catalytic reaction steps, respectively. Our results reconcile previous experimental observations for human and bacterial OGA and will aid the development of more effective OGA inhibitors for diseases associated with impaired O-GlcNAcylation.
More Information
Statistics

Downloads

Downloads per month over past year

Metrics

Altmetric Badge

Dimensions Badge

Share
Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email

Actions (login required)

View Item View Item