Probably involved in the polymerization of enterobacterial common antigen (ECA) trisaccharide repeat units. Required for the assembly of the phosphoglyceride-linked form of ECA (ECA(PG)) and the water-soluble cyclic form of ECA (ECA(CYC)). Bacterial outer membrane biogenesis; enterobacterial common antigen biosynthesis. Probably part of a complex composed of WzxE, WzyE and WzzE. Belongs to the WzyE family. Was originally thought to be WecF, the 4-alpha-L-fucosyltransferase.