Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
NCBI PubMed ID: 10373459Journal NLM ID: 2985121RPublisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
Correspondence: raetz
biochem.duke.edu
Institutions: Department of Biochemistry, Duke University Medical Center, Box 3711, Durham, North Carolina 27710, USA, Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
Two-thirds of the lipid A in wild-type Escherichia coli K12 is a hexa-acylated disaccharide of glucosamine in which monophosphate groups are attached at positions 1 and 4'. The remaining lipid A contains a monophosphate substituent at position 4' and a pyrophosphate moiety at position 1. The biosynthesis of the 1-pyrophosphate unit is unknown. Its presence is associated with lipid A translocation to the outer membrane (Zhou, Z., White, K. A., Polissi, A., Georgopoulos, C., and Raetz, C. R. Haemophilus (1998) J. Biol. Chem. 273, 12466-12475). To determine if a phosphatase regulates the amount of the lipid A 1-pyrophosphate, we grew cells in broth containing nonspecific phosphatase inhibitors. Na2WO4 and sodium fluoride increased the relative amount of the 1-pyrophosphate slightly. Remarkably, NH4VO3-treated cells generated almost no 1-pyrophosphate, but made six major new lipid A derivatives (EV1 to EV6). Matrix-assisted laser desorption ionization/time of flight mass spectrometry of purified EV1 to EV6 indicated that these compounds were lipid A species substituted singly or in combination with palmitoyl, phosphoethanolamine, and/or aminodeoxypentose residues. The aminodeoxypentose residue was released by incubation in chloroform/methanol (4:1, v/v) at 25 degrees C, and was characterized by 1H NMR spectroscopy. The chemical shifts and vicinal coupling constants of the two anomers of the aminodeoxypentose released from EV3 closely resembled those of synthetic 4-amino-4-deoxy-L-arabinose. NH4VO3-induced lipid A modification did not require the PhoP/PhoQ two-component regulatory system, and also occurred in E. coli msbB or htrB mutants. The lipid A variants that accumulate in NH4VO3-treated E. coli K12 are the same as many of those normally found in untreated Salmonella typhimurium and Salmonella minnesota, demonstrating that E. coli K12 has latent enzyme systems for synthesizing these important derivatives.
Escherichia coli, lipid A, modification, Salmonella typhimurium, 4-amino-4-deoxy-L-arabinose, E. coli K-12, metavanadate, NH4VO3
Structure type: oligomer
Location inside paper: p.18506, fig.1C
Compound class: lipid A
Contained glycoepitopes: IEDB_120354,IEDB_123890,IEDB_135394,IEDB_135515,IEDB_141181,IEDB_141807,IEDB_151531,IEDB_176772,IEDB_534864
Methods: 1H NMR, PCR, FAB-MS, TLC, mild acid hydrolysis, MALDI-TOF MS, radiolabeling, genetic methods
Comments, role: E. coli K-12 with 25 mM metavanadate; proposed major species of the lipid A
Related record ID(s): 5983, 31288, 31289
NCBI Taxonomy refs (TaxIDs): 83333
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There is only one chemically distinct structure:
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