Definition:

Catalyzes the transfer of L-fucose, from a guanosine diphosphate-beta-L-fucose, to the N-acetyl glucosamine (GlcNAc) of a distal lactosamine unit of a glycoprotein or a glycolipid-linked polylactosamine chains through an alpha-1,3 glycosidic linkage and participates in particular to the Lewis x (Lex)/CD15 epitope biosynthesis in neurons which allows cell differentiation, cell adhesion, and initiation of neurite outgrowth. Also fucosylates di-, tri- and tetraantennary N-glycans linked to glycoproteins and the inner lactosamine unit of the alpha2,3-sialylated polylactosamine resulting in sLex (CD15s) epitope synthesis. Furthermore, it is capable of synthesizing Lewis a (Lea), although to a lesser extent than Lex and Lewis y (Ley) and to confer SELE-dependent, but not SELL- and SELP-selectin-dependent, cell rolling and adhesion by enhancing Lex and sLex synthesis. May also fucosylate the internal LacNAc unit of the polylactosamine chain to form VIM-2 antigen that serves as recognition epitope for SELE.