Glucoside Xylosyltransferase 2 (GXYLT2)

GXYLT2 is a xylosyltransferase (EC 2.4.2.-) that adds the first xylose to O-glucose-modified residues in the epidermal growth factor (EGF) repeats of proteins such as NOTCH1.

By searching a database for sequences similar to the catalytic domain of UGGT1, Sethi et al. (2010) identified human GXYLT1 and GXYLT2. The deduced 443-amino acid GXYLT2 protein contains a short N-terminal cytoplasmic domain, followed by a transmembrane domain, a stem region, and a large glycosyltransferase domain containing the conserved DxD motif. GXYLT1 and GXYLT2 share about 50% amino acid identity, with most amino acid differences in the stem region, where GXYLT2 has an arginine- and proline-rich insertion that is not found in GXYLT1.