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Lipid IVA 4-amino-4-deoxy-L-arabinosyltransferase (EC 2.4.2.43, 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 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 ${\displaystyle \rightleftharpoons }$ alpha-Kdo-(2->4)-alpha-Kdo-(2->6)--lipid A + ditrans, octacis-undecaprenyl phosphate

(2) 4-amino-4-deoxy-alpha-L-arabinopyranosyl ditrans, octacis-undecaprenyl phosphate + lipid IVA ${\displaystyle \rightleftharpoons }$ 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 ${\displaystyle \rightleftharpoons }$ 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.

References

1. Trent MS, Ribeiro AA, Lin S, Cotter RJ, Raetz CR (November 2001). "An inner membrane enzyme in Salmonella and Escherichia coli that transfers 4-amino-4-deoxy-L-arabinose to lipid A: induction on polymyxin-resistant mutants and role of a novel lipid-linked donor". The Journal of Biological Chemistry. 276 (46): 43122–31. doi:10.1074/jbc.m106961200. PMID 11535604.
2. Trent MS, Ribeiro AA, Doerrler WT, Lin S, Cotter RJ, Raetz CR (November 2001). "Accumulation of a polyisoprene-linked amino sugar in polymyxin-resistant Salmonella typhimurium and Escherichia coli: structural characterization and transfer to lipid A in the periplasm". The Journal of Biological Chemistry. 276 (46): 43132–44. doi:10.1074/jbc.m106962200. PMID 11535605.
3. Zhou Z, Ribeiro AA, Lin S, Cotter RJ, Miller SI, Raetz CR (November 2001). "Lipid A modifications in polymyxin-resistant Salmonella typhimurium: PMRA-dependent 4-amino-4-deoxy-L-arabinose, and phosphoethanolamine incorporation". The Journal of Biological Chemistry. 276 (46): 43111–21. doi:10.1074/jbc.m106960200. PMID 11535603.
4. 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. PMID 16226890.
5. Impellitteri NA, Merten JA, Bretscher LE, Klug CS (January 2010). "Identification of a functionally important loop in Salmonella typhimurium ArnT". Biochemistry. 49 (1): 29–35. doi:10.1021/bi901572f. PMC 2805049. PMID 19947657.

External links

• Lipid+IVA+4-amino-4-deoxy-L-arabinosyltransferase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

• Biology

• EC 2.4.2