Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Salmonella enterica [ICD11:
XN5VC 
]
The structure was elucidated in this paperNCBI PubMed ID: 15014080Publication DOI: 10.1074/jbc.M401275200Journal NLM ID: 2985121RPublisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
Correspondence: millersi
u.washington.edu
Institutions: Department of Microbiology, University of Washington, Seattle, WA 98195, USA
Toll-like receptor 4 (TLR4)-mediated responses, which are induced by the lipid A portion of lipopolysaccharide, are important for host defense against Salmonellae infection. A variety of different data indicate that the acylation state of lipid A can alter TLR4-mediated responses. The S. typhimurium virulence gene product PhoP/PhoQ signals the presence of host microenvironments to regulate the expression of a lipid A 3-O-deacylase, PagL, and a lipid A palmitoyltransferase, PagP. We now demonstrate that 3-O-deacylation and palmitoylation of lipid A decreases its ability to induce TLR4-mediated signaling. Deacylated lipid A, deacylated and palmitoylated lipid A, palmitoylated lipid A, and unmodified lipid A species were purified from Escherichia coli heterologously expressing PagL and/or PagP. The purified lipid A preparations showed spectra of a single lipid A species on mass spectrometry and gave a single band on thin layer chromatography. The activity of purified lipid A species was examined using human and mouse cell lines that express recombinant human TLR4. Compared with unmodified lipid A, the modified lipid A species are 30-100-fold less active in the ability to induce NF-kappaB-dependent reporter activation. These results suggest that the lipid A modifications reduce TLR4-signaling as part of Salmonellae adaptation to host environments.
Lipopolysaccharide, Escherichia coli, lipid A, mass spectrometrySalmonella typhimurium
Structure type: oligomer
Location inside paper: p.20045, fig.1, P-lipid A
Compound class: lipid A
Contained glycoepitopes: IEDB_135394,IEDB_137340,IEDB_141181,IEDB_141807,IEDB_151531,IEDB_176772,IEDB_534864
Methods: TLC, MALDI-TOF MS, biological assays, genetic methods, biochemical methods
Enzymes that release or process the structure: PagP
Comments, role: Palmitoylated lipid A (P-lipid A)
Related record ID(s): 9525, 31329, 31330
NCBI Taxonomy refs (TaxIDs): 90371
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
report error
(later renamed to: Salmonella enterica ssp. enterica sv. Typhimurium)