This domain is found C-terminal in N-acetylglucosaminyltransferase IV (MGAT4, GnT-IV) and related proteins. N-Acetylglucosaminyltransferases (GnTs) take part in the formation of branches in the biosynthesis of complex-type sugar chains. In vertebrate ...
This domain is found C-terminal in N-acetylglucosaminyltransferase IV (MGAT4, GnT-IV) and related proteins. N-Acetylglucosaminyltransferases (GnTs) take part in the formation of branches in the biosynthesis of complex-type sugar chains. In vertebrates, six GnTs, designated as GnT-I to -VI, which catalyse the transfer of GlcNAc to the core mannose residues of Asn-linked sugar chains, have been identified. GnT-IV (EC:2.4.1.145) catalyses the transfer of GlcNAc from UDP-GlcNAc to the GlcNAc1-2Man1-3 arm of core oligosaccharide [Gn2(22)core oligosaccharide] and forms GlcNAc1-4(GlcNAc1-2)Man1-3 structure on the core oligosaccharide (Gn3(2,4,2)core oligosaccharide). This domain selectively interacts with the product N-glycans having a beta1-4 GlcNAc branch. Mutation of the residue critical for the sugar recognition impairs the enzymatic activity, suggesting that the lectin domain is a regulatory subunit for efficient catalytic reaction [1]. This domain adopts a beta-sandwich fold typical for galactose binding domains.