Crystal Structure-Based Analysis of Human Glucuronyltransferase 1

Glucuronyltransferase I (GlcAT-I) is a key enzyme in heparan/chondroitin biosynthesis (1). The X-ray crystal structure of human GlcAT-1 has been solved in the presence of both UDP and substrate analog. The structure reveals a two sub-domain structure known as the SGC domain. Donor substrate-binding site resides in the N-terminal sub-domain, while acceptor substrate-binding site is located in the C-terminal sub-domain. In addition to conserved residues responsible for the donor binding, various residues that interact with the acceptor molecule have now been identified. The GlcAT-1 provides the structural basis for understanding the structure and function of glycosyltransferases.