FUT4

This gene encodes α1,3-fucosyltransferase 4 (FUT4). Six α1,3-fucosyltransferases (α3FUT): FUT3, FUT4, FUT5, FUT6, FUT7, and FUT9 are known and confirmed that each enzyme has a characteristic substrate specificity in vitro. Except FUT7, these have activity to transfer fucose to GlcNAc of the type 2 lactosamine structure (Galβ1-4GlcNAcβ1-3-R) with α1-3-linkage. FUT4 is related to synthesis of Lewis x (Lex) carbohydrate antigen, one of the Lewis blood group antigens, but not involved in synthesis of sialyl Lewis x (sLex) antigen. FUT4 has activity to transfer fucose from the GlcNAc residue of the reducing end (internal structure) to the non-reducing end (terminal structure) on the oligosaccharide substrates consisting of polylactosamine (poly-N-acetyllactosamine).