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 3 of the pentasaccharide. Cell surface structure biogenesis; S-layer biogenesis. Mutants contain only mono- and disaccharide-modified phosphodolichols and exhibit defective or limited motility. Belongs to the glycosyltransferase 2 family.