Mannosyl Alpha-1,4-Glycoprotein Beta-1,4-N-Acetylglucosaminyltransferase (MGAT3)

MGAT3 transfers a GlcNAc residue to the beta-linked mannose of the trimannosyl core of N-linked oligosaccharides and produces a bisecting GlcNAc. Multiple alternatively spliced variants, encoding the same protein, have been identified.The predicted 531-amino acid MGAT3 protein has a domain structure typical of that of glycosyltransferases. The structure of MGAT3 includes a short N-terminal cytoplasmic domain, a transmembrane domain, a 'neck' region, and a long C-terminal tail containing the catalytic domain. MGAT3 contains a sequence that is homologous to sequences in EGF-like domains; the adhesion recognition sequence leu-asp-val; and 4 potential N-linked glycosylation sites. Human and rat MGAT share 91% amino acid sequence identity.