Glycosyltransferase family 10 comprises enzymes with five known activities;
galactoside 3(4)-L-fucosyltransferase (),
galactoside 3-fucosyltransferase (), peptide O-fucosyltransferase (), glycoprotein 3-α-L-fucosyltransferase () and the recently defined EMI-domain-modifying peptide O-fucosyltransferases (mammalian FUT10 and FUT11, renamed POFUT3 and POFUT4). The galactoside 3-fucosyltransferases display similarities with the alpha-2 and alpha-6-fucosyltranferases. The biosynthesis of the carbohydrate antigen
sialyl-Lewis X (sLe(x)) is dependent on the activity of an galactoside 3-fucosyltransferase. This enzyme catalyses the transfer of fucose from GDP-beta-fucose to the 3-OH of
N-acetylglucosamine present in
lactosamine acceptors. While the aforementioned POFUT3 and POFUT4 enzymes are included in glycosyltransferase family 10, POFUT1 is the sole member of family 65 [https://www.cazy.org/GT65.html while POFUT2 is the sole member of family 68
FUT8 is the sole enzyme in mammals adding core α1,6-fucose to N-linked glycans (). It is classified as a glycosyltransferase family 23 member [https://www.cazy.org/GT23.html. Fucosyltransferases in non-mammals, e.g., plants and nematodes follow a different numbering scheme. ==Role in preventing UTIs==