Fucosyltransferase

A fucosyltransferase is an enzyme that transfers an L-fucose sugar from a GDP-fucose (guanosine diphosphate-fucose) donor substrate to an acceptor substrate. The acceptor substrate can be another sugar such as the transfer of a fucose to a core GlcNAc (N-acetylglucosamine) sugar as in the case of N-linked glycosylation, or to a protein, as in the case of O-linked glycosylation produced by O-fucosyltransferase. There are various fucosyltransferases in mammals, the vast majority of which, are located in the Golgi apparatus. The O-fucosyltransferases have recently been shown to localize to the endoplasmic reticulum (ER).

Some of the proteins in this group are responsible for the molecular basis of the blood group antigens, surface markers on the outside of the red blood cell membrane. Most of these markers are proteins, but some are carbohydrates attached to lipids or proteins [Reid M.E., Lomas-Francis C. The Blood Group Antigen FactsBook Academic Press, London / San Diego, (1997)]. Galactoside 3(4)-L-fucosyltransferase (EC 2.4.1.65) belongs to the Lewis blood group system and is associated with Le(a/b) antigen.