Dolichyl Phosphate-N-Acetylglucosaminephosphotransferase 1 (DPAGT1)

DPAGT1 is an enzyme that catalyzes the first step in the dolichol-linked oligosaccharide pathway for glycoprotein biosynthesis. This enzyme belongs to the glycosyltransferase family 4. This protein is an integral membrane protein of the endoplasmic reticulum. The congenital disorder of glycosylation type Ij is caused by mutation in the gene encoding this enzyme. The cDNA encodes a deduced 400-amino acid protein with a calculated molecular mass of 44.7 kD. DPAGT1 contains an N-terminal signal peptide, 2 potential dolichol-binding sequences, and 4 sites for N-glycosylation. It shares 93% amino acid homology with hamster Dpagt, including 100% identity in the dolichol-binding region, and 42% homology with S. cerevisiae GlcNAc-1-P transferase.