Plays a role in the biosynthesis of B-band O antigen for serotype O5. Catalyzes the NAD-dependent oxidation of UDP-N-acetylglucosaminuronic acid (UDP-D-GlcNAcA) to UDP-2-acetamido-2-deoxy-3-oxo-D-glucuronic acid (UDP-3-oxo-D-GlcNAcA). Cannot use UDP-GlcNAc or UDP-GalNAc as the nucleotide sugar substrate, and can use only poorly UDP-D-glucuronic acid (UDP-GlcA). Undergoes an NAD(+) recycling mechanism using 2-oxoglutarate as an oxidant. NAD(+) + UDP-N-2-acetamido-2-deoxy-alpha-D-glucuronate = H(+) + NADH + UDP-2-acetamido-2-deoxy-alpha-D-ribo-hex-3-uluronate 2-hydroxyglutarate + NAD(+) = 2-oxoglutarate + H(+) + NADH Optimum pH is 8.0 for the coupled WbpB/WbpE reaction. Optimum temperature is 30 degrees Celsius for the coupled WbpB/WbpE reaction. Bacterial outer membrane biogenesis; LPS O-antigen biosynthesis. Homotetramer. Seems to proceed via a ping-pong reaction mechanism. Belongs to the Gfo/Idh/MocA family.