4-galactosyl-N-acetylglucosaminide 3-alpha-L-fucosyltransferase FUT5

Catalyzes preferentially the transfer of L-fucose, from a guanosine diphosphate-beta-L-fucose, to the N-acetyl-beta-D-glucosamine (GlcNAc) of an N-acetyllactosamine unit (type 2 chain) of an oligosaccharide, or a glycoprotein- and a glycolipid-linked N-acetyllactosamine unit via an alpha (1,3) linkage and participates in the surface expression of VIM-2, Lewis X/SSEA-1 and sialyl Lewis X antigens. Preferentially transfers fucose to the GlcNAc of an internal N-acetyllactosamine unit of a poly-N-acetyllactosamine chain acceptor substrate. Also catalyzes to a lesser extend the transfer of L-fucose to the GlcNAc of a type 1 (beta-D-galactosyl-(1->3)-N-acetyl-beta-D-glucosaminyl) or H-type 1 (alpha-L-Fuc-(1->2)-beta-D-Gal-(1->3)-D-GlcNAc) chain oligosaccharide via an alpha (1,4) linkage. Preferentially catalyzes sialylated type 2 oligosaccharide acceptors over neutral type 2 or H type 2 (alpha-L-Fuc-(1->2)-beta-D-Gal-(1->4)-D-GlcNAc) oligosaccharide acceptors. Lactose-based structures are also acceptor substrates.