Lipid IVA 4-amino-4-deoxy-L-arabinosyltransferase

Lipid IVA 4-amino-4-deoxy-L-arabinosyltransferase (, 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 name 4-amino-4-deoxy-alpha-L-arabinopyranosyl ditrans, octacis-undecaprenyl phosphate:lipid IVA 4-amino-4-deoxy-L-arabinopyranosyltransferase. 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 $$\rightleftharpoons$$ alpha-Kdo-(2->4)-alpha-Kdo-(2->6)-[4-P-L-Ara4N]-lipid A + ditrans, octacis-undecaprenyl phosphate
 * (2) 4-amino-4-deoxy-alpha-L-arabinopyranosyl ditrans, octacis-undecaprenyl phosphate + lipid IVA $$\rightleftharpoons$$ lipid IIA + ditrans, octacis-undecaprenyl phosphate
 * (3) 4-amino-4-deoxy-alpha-L-arabinopyranosyl ditrans, octacis-undecaprenyl phosphate + alpha-Kdo-(2->4)-alpha-Kdo-(2->6)-lipid IVA $$\rightleftharpoons$$ 4'-alpha-L-Ara4N-alpha-Kdo-(2->4)-alpha-Kdo-(2->6)-lipid IVA + ditrans, octacis-undecaprenyl phosphate

This integral membrane protein is present in the inner membrane of certain Gram negative endobacteria.