Download MendeleyStructural Snapshots of alpha-1,3-Galactosyltransferase with Native Substrates: Insight into the Catalytic Mechanism of Retaining Glycosyltransferases.
Albesa-Jove, D., Sainz-Polo, M.A., Marina, A., Guerin, M.E.(2017) Angew Chem Int Ed Engl 56: 14853-14857
- PubMed: 28960760
- DOI: https://doi.org/10.1002/anie.201707922
- Primary Citation of Related Structures:
5NR9, 5NRB, 5NRD, 5NRE - PubMed Abstract:
Glycosyltransferases (GTs) are a key family of enzymes that catalyze the synthesis of glycosidic bonds in all living organisms. The reaction involves the transfer of a glycosyl moiety and can proceed with retention or inversion of the anomeric configuration. To date, the catalytic mechanism of retaining GTs is a topic of great controversy, particularly for those enzymes containing a putative nucleophilic residue in the active site, for which the occurrence of a double-displacement mechanism has been suggested. We report native ternary complexes of the retaining glycosyltransferase α-1,3-galactosyltransferase (α3GalT) from Bos taurus, which contains such a nucleophile in the active site, in a productive mode for catalysis in the presence of its sugar donor UDP-Gal, the acceptor substrate lactose, and the divalent cation cofactor. This new experimental evidence supports the occurrence of a front-side substrate-assisted S N i-type reaction for α3GalT, and suggests a conserved common catalytic mechanism among retaining GTs.
Organizational Affiliation:
Structural Biology Unit-CIC bioGUNE, Technological Park of Bizkaia-Ed 800, 48160, Derio, Vizcaya, Spain.
