Structure of bovine alpha-1,3-galactosyltransferase and its complexes withUDP and DPGal inferred from molecular modeling

Rao, M Tvaroska, I

M. Rao et I. Tvaroska, Structure of bovine alpha-1,3-galactosyltransferase and its complexes withUDP and DPGal inferred from molecular modeling, PROTEINS, 44(4), 2001, pp. 428-434

21

INGLESE

Article

Biochemistry & Biophysics

PROTEINS-STRUCTURE FUNCTION AND GENETICS

0887-3585 → ACNP

44

4

2001

428 - 434

ISI

0887-3585(20010901)44:4<428:SOBAAI>2.0.ZU;2-O

A homology model of alpha -1,3-galactosyltransferase (alpha -1,3-GalT), the retaining enzyme responsible for the formation of alpha -galactosyl epitop es, has been developed by means of molecular modeling using the SpsA glycos yltransferase structure. A protein-ligand docking approach was used to mode l alpha -1,3-GalT complexed with UDP and UDP-Gal. The comparison of structu ral features found in the alpha -1,3-GalT homology model with available str uctural data on this class of enzymes revealed similarities in the UDP-bind ing pocket. In the predicted structure of the complexes, the pyrophosphate interacts with the DVD motif (Asp-225, Val-226, and Asp-227) of alpha -1,3- GalT through the Mn2+ cation. The uridine part of the UDP binds into the we ll-defined cavity that consists of Phe-134, Tyr-139, Ile-140, Val-136, Arg- 194, Arg-202, Lys-209, Asp-173, His-218, and Thr-137 in a conformation that is generally observed in the crystal structures of other glycosyltransfera se complexes. Proteins 2001;44:428-434. (C) 2001 Wiley-Liss, Inc.