5NRB

A Native Ternary Complex of Alpha-1,3-Galactosyltransferase (a-3GalT) Supports a Conserved Reaction Mechanism for Retaining Glycosyltransferases - alpha-3GalT in complex with Co2+, UDP-Gal and lactose - a3GalT-Co2+-UDP-Gal-LAT-1

Summary for 5NRB

• Entry DOI: 10.2210/pdb5nrb/pdb
• Related PRD ID: PRD_900004
• Descriptor: N-acetyllactosaminide alpha-1,3-galactosyltransferase, beta-D-galactopyranose-(1-4)-beta-D-glucopyranose, COBALT (II) ION, ... (5 entities in total)
• Functional Keywords: glycosyltransferase, gta, transferase
• Biological source: Bos taurus (Bovine)
• Cellular location: Golgi apparatus, Golgi stack membrane; Single-pass type II membrane protein: P14769
• Total number of polymer chains: 2
• Total formula weight: 70323.75

Authors

Albesa-Jove, D.,Marina, A.,Sainz-Polo, M.A.,Guerin, M.E. (deposition date: 2017-04-22, release date: 2017-10-11, Last modification date: 2024-01-17)

Primary citation

Albesa-Jove, D.,Sainz-Polo, M.A.,Marina, A.,Guerin, M.E.
Structural Snapshots of alpha-1,3-Galactosyltransferase with Native Substrates: Insight into the Catalytic Mechanism of Retaining Glycosyltransferases.
Angew. Chem. Int. Ed. Engl., 56:14853-14857, 2017

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 i-type reaction for α3GalT, and suggests a conserved common catalytic mechanism among retaining GTs.

PubMed: 28960760
DOI: 10.1002/anie.201707922

Experimental method

X-RAY DIFFRACTION (2.24 Å)