This entry represents ArnB, which catalyzes the conversion of UDP-4-keto-arabinose (UDP-Ara4O) to UDP-4-amino-4-deoxy-L-arabinose (UDP-L-Ara4N). The modified arabinose is attached to lipid A and is required for resistance to polymyxin and cationic antimicrobial peptides. UDP-4-amino-4-deoxy-L-arabinose-oxoglutarate aminotransferase, ArnB