Document Type
Article
Publication Date
1-1-2008
Description
One-third of the lipid A found in the Escherichia coli outer membrane contains an unsubstituted diphosphate unit at position 1 (lipid A 1-diphosphate). We now report an inner membrane enzyme, LpxT (YeiU), which specifically transfers a phosphate group to lipid A, forming the 1-diphosphate species. 32P-labelled lipid A obtained from lpxT mutants do not produce lipid A 1-diphosphate. In vitro assays with Kdo2-[4′- 32P]lipid A as the acceptor shows that LpxT uses undecaprenyl pyrophosphate as the substrate donor. Inhibition of lipid A 1-diphosphate formation in wild-type bacteria was demonstrated by sequestering undecaprenyl pyrophosphate with the cyclic polypeptide antibiotic bacitracin, providing evidence that undecaprenyl pyrophosphate serves as the donor substrate within whole bacteria. LpxT-catalysed phosphorylation is dependent upon transport of lipid A across the inner membrane by MsbA, a lipid A flippase, indicating a periplasmic active site. In conclusion, we demonstrate a novel pathway in the periplasmic modification of lipid A that is directly linked to the synthesis of undecaprenyl phosphate, an essential carrier lipid required for the synthesis of various bacterial polymers, such as peptidoglycan.
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Citation Information
Touzé, Thierry; Tran, An X.; Hankins, Jessica V.; Mengin-Lecreulx, Dominique; and Trent, M. Stephen. 2008. Periplasmic Phosphorylation of Lipid a Is Linked to the Synthesis of Undecaprenyl Phosphate. Molecular Microbiology. Vol.67(2). 264-277. https://doi.org/10.1111/j.1365-2958.2007.06044.x PMID: 18047581 ISSN: 0950-382X
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© 2007 The Authors Journal compilation © 2007 Blackwell Publishing Ltd
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