Lipid IVA 4-amino-4-deoxy-L-arabinosyltransferase (EC2.4.2.43, undecaprenyl phosphate-alpha-L-Ara4N transferase, 4-amino-4-deoxy-L-arabinose lipid A transferase, polymyxin resistance protein PmrK, arnT (gene)) is an enzyme with systematic name4-amino-4-deoxy-alpha-L-arabinopyranosyl ditrans, octacis-undecaprenyl phosphate:lipid IVA 4-amino-4-deoxy-L-arabinopyranosyltransferase.[1][2][3][4][5] This enzyme catalyses the following chemical reaction
(1) 4-amino-4-deoxy-alpha-L-arabinopyranosyl ditrans, octacis-undecaprenyl phosphate + alpha-Kdo-(2->4)-alpha-Kdo-(2->6)-lipid A alpha-Kdo-(2->4)-alpha-Kdo-(2->6)-[4-P-L-Ara4N]-lipid A + ditrans, octacis-undecaprenyl phosphate
^Bretscher LE, Morrell MT, Funk AL, Klug CS (March 2006). "Purification and characterization of the L-Ara4N transferase protein ArnT from Salmonella typhimurium". Protein Expression and Purification. 46 (1): 33–9. doi:10.1016/j.pep.2005.08.028. PMID16226890.