1GX0

ALPHA-,1,3 GALACTOSYLTRANSFERASE - BETA-D-GALACTOSE COMPLEX

Summary for 1GX0

• Entry DOI: 10.2210/pdb1gx0/pdb
• Related: 1FG5 1G8O 1G93 1GWV 1GWW 1GX4 1K4V 1O7O 1O7Q 1O7R
• Descriptor: N-ACETYLLACTOSAMINIDE ALPHA-1,3-GALACTOSYLTRANSFERASE, URIDINE-5'-DIPHOSPHATE, MANGANESE (II) ION, ... (6 entities in total)
• Functional Keywords: galactosyltransferase, blood group sugars, lactose, n-acetyl lactosamine, transferase, glycosyltransferase
• 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: 69462.87

Authors

Boix, E.,Zhang, Y.,Swaminathan, G.J.,Brew, K.,Acharya, K.R. (deposition date: 2002-03-26, release date: 2003-03-20, Last modification date: 2023-12-13)

Primary citation

Boix, E.,Zhang, Y.,Swaminathan, G.J.,Brew, K.,Acharya, K.R.
Structural Basis of Ordered Binding of Donor and Acceptor Substrates to the Retaining Glycosyltransferase, Alpha -1,3 Galactosyltransferase
J.Biol.Chem., 277:28310-, 2002

PubMed Abstract: Bovine alpha-1,3-galactosyltransferase (alpha3GT) catalyzes the synthesis of the alpha-galactose (alpha-Gal) epitope, the target of natural human antibodies. It represents a family of enzymes, including the histo blood group A and B transferases, that catalyze retaining glycosyltransfer reactions of unknown mechanism. An initial study of alpha3GT in a crystal form with limited resolution and considerable disorder suggested the possible formation of a beta-galactosyl-enzyme covalent intermediate (Gastinel, L. N., Bignon, C., Misra, A. K., Hindsgaul, O., Shaper, J. H., and Joziasse, D. H. (2001) EMBO J. 20, 638-649). Highly ordered structures are described for complexes of alpha3GT with donor substrate, UDP-galactose, UDP- glucose, and two acceptor substrates, lactose and N-acetyllactosamine, at resolutions up to 1.46 A. Structural and calorimetric binding studies suggest an obligatory ordered binding of donor and acceptor substrates, linked to a donor substrate-induced conformational change, and the direct participation of UDP in acceptor binding. The monosaccharide-UDP bond is cleaved in the structures containing UDP-galactose and UDP-glucose, producing non-covalent complexes containing buried beta-galactose and alpha-glucose. The location of these monosaccharides and molecular modeling suggest that binding of a distorted conformation of UDP-galactose may be important in the catalytic mechanism of alpha3GT.

PubMed: 12011052
DOI: 10.1074/JBC.M202631200

Experimental method

X-RAY DIFFRACTION (1.8 Å)