Involved in cell wall biosynthesis. Is both necessary and sufficient for the addition of the terminal fucosyl residue on xyloglucan side chains, but is not involved in the fucosylation of other cell wall components (PubMed:10373113, PubMed:11743104, PubMed:11854459, PubMed:14730072). Associates with other xyloglucan-synthesizing enzymes to form multiprotein complexes for xyloglucan synthesis in the Golgi (PubMed:25392066). Homodimer (PubMed:25392066). Interacts with MUR3, XLT2, XXT2 and XXT5 (PubMed:25392066). Membrane-bound form in trans cisternae of Golgi. Expressed in roots, stems, leaves, flowers, siliques and seedlings. Belongs to the glycosyltransferase 37 family.