Substrate‐Guided Front‐Face Reaction Revealed by Combined Structural Snapshots and Metadynamics for the Polypeptide N‐Acetylgalactosaminyltransferase 2

Peer reviewed: 
Yes, item is peer reviewed.
Scholarly level: 
Faculty/Staff
Final version published as: 

Lira-Navarrete, E., Iglesias-Fernández, J., Zandberg, W. F., Compañón, I., Kong, Y., Corzana, F., Pinto, B. M., Clausen, H., Peregrina, J. M., Vocadlo, D. J., Rovira, C., & Hurtado-Guerrero, R. (2014). Substrate-Guided Front-Face Reaction Revealed by Combined Structural Snapshots and Metadynamics for the Polypeptide N-Acetylgalactosaminyltransferase 2. Angewandte Chemie International Edition, 53(31), 8206–8210. https://doi.org/10.1002/anie.201402781

Date created: 
2014-06-20
Identifier: 
DOI: 10.1002/anie.201402781
Keywords: 
Acetamido groups
Proteins
Quantum mechanics/molecular mechanics
SNi-type reactions
X-ray diffraction
Abstract: 

The retaining glycosyltransferase GalNAc-T2 is a member of a large family of human polypeptide GalNActransferases 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 atomicelectronic 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 andenforce a front-face SNi-type reaction in which the substrate Nacetyl sugar substituent coordinates efficient glycosyl transfer.

Language: 
English
Document type: 
Article
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Rights remain with the authors.
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