Crystal structure of beta 1,3-glucuronyltransferase I in complex with active donor substrate UDP-GlcUA.Pedersen, L.C., Darden, T.A., Negishi, M.
(2002) J Biol Chem 277: 21869-21873
- PubMed: 11950836
- DOI: https://doi.org/10.1074/jbc.M112343200
- Primary Citation of Related Structures:
- PubMed Abstract:
Beta1,3-glucuronyltransferase (GlcAT-I) is an essential enzyme involved in heparan sulfate and chondroitin sulfate biosynthesis. GlcAT-I is an inverting glycosyltransferase that catalyzes the transfer of glucuronic acid (GlcUA) to the common growing linker region Galbeta1-3Galbeta1-4Xyl that is attached to a serine side chain of a core protein. Previously the structure of GlcAT-I has been solved in the presence of the donor product UDP and an acceptor analog Galbeta1-3Galbeta1-4Xyl (Pedersen, L. C., Tsuchida, K., Kitagawa, H., Sugahara, K., Darden, T. A. & Negishi, M. (2000) J. Biol. Chem. 275, 34580-34585). Here we report the x-ray crystal structure of GlcAT-I in complex with the complete donor UDP-GlcUA, thereby providing structures of an inverting glycosyltransferase in which both the complete donor and acceptor substrates are present in the active site. This structure supports the in-line displacement reaction mechanism previously proposed. It also provides information on the essential amino acid residues that determine donor substrate specificity.
Laboratory of Reproductive and Developmental Toxicology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.