Substrate-guided front-face reaction revealed by combined structural snapshots and metadynamics for the polypeptide N -acetylgalactosaminyltransferase 2

DOI: 10.1002/anie.201402781
PMID: 24954443

Authors: Erandi Lira (University of Zaragoza) , Javier Iglesias-Fernandez (Universitat de Barcelona) , Wesley F. Zandberg (Simon Fraser University) , Ismael Compañón (Universidad de La Rioja) , Yun Kong (University of Copenhagen) , Francisco Corzana (Universidad de La Rioja) , B. Mario Pinto (Simon Fraser University) , Henrik Clausen (University of Copenhagen) , Jesús M. Peregrina (Universidad de La Rioja) , David J. Vocadlo (Simon Fraser University) , Carme Rovira (Universitat de Barcelona) , Ramon Hurtado-Guerrero (University of Zaragoza)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Angewandte Chemie International Edition , VOL 53 (31) , PAGES 8206 - 8210

State: Published (Approved)
Published: July 2014
Diamond Proposal Number(s): 8035

Abstract: The retaining glycosyltransferase GalNAc-T2 is a member of a large family of human polypeptide GalNAc-transferases that is responsible for the post-translational modification of many cell-surface proteins. By the use of combined structural and computational approaches, we provide the first set of structural snapshots of the enzyme during the catalytic cycle and combine these with quantum-mechanics/molecular-mechanics (QM/MM) metadynamics to unravel the catalytic mechanism of this retaining enzyme at the atomic-electronic level of detail. Our study provides a detailed structural rationale for an ordered bi-bi kinetic mechanism and reveals critical aspects of substrate recognition, which dictate the specificity for acceptor Thr versus Ser residues and enforce a front-face SN i-type reaction in which the substrate N-acetyl sugar substituent coordinates efficient glycosyl transfer.

Journal Keywords: acetamido groups; proteins; quantum mechanics/ molecular mechanics; SNi-type reactions; X-ray diffraction

Diamond Keywords: Enzymes

Subject Areas: Medicine, Biology and Bio-materials


Instruments: I04-1-Macromolecular Crystallography (fixed wavelength) , I24-Microfocus Macromolecular Crystallography

Added On: 24/09/2014 10:42

Discipline Tags:

Health & Wellbeing Structural biology Drug Discovery Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)