Plays a role in the biosynthesis of B-band O antigen for serotype O5. Catalyzes the C-6 dehydrogenation of UDP-D-GlcNAc to UDP-N-acetylglucosaminuronic acid (UDP-D-GlcNAcA). H2O + 2 NAD(+) + UDP-N-acetyl-alpha-D-glucosamine = 3 H(+) + 2 NADH + UDP-N-2-acetamido-2-deoxy-alpha-D-glucuronate A monovalent cation. NH4(+) and K(+) are the most effective. Optimum pH is 8.0-9.0. Optimum temperature is 33-37 degrees Celsius. Active from temperatures ranging from 0 degrees Celsius to 65 degrees Celsius. Bacterial outer membrane biogenesis; LPS O-antigen biosynthesis. Homotrimer in solution. May also exist in a dimeric or tetrameric form. Belongs to the UDP-glucose/GDP-mannose dehydrogenase family.