Involved in the assembly of a N-linked pentasaccharide that decorates the S-layer glycoprotein and flagellins. Catalyzes the addition to the dolichol phosphate carrier of the hexuronic acid found at position 4 of the pentasaccharide. Cell surface structure biogenesis; S-layer biogenesis. Could be an integral membrane protein. Mutants contain only mono-, di- and trisaccharide-modified phosphodolichols. Deletion does not alter cell growth or stability of the S-layer. Mutants exhibit defective or limited motility. Belongs to the glycosyltransferase 2 family.