Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
The structure was elucidated in this paperNCBI PubMed ID: 18070877Journal NLM ID: 2985121RPublisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
Correspondence: bishopr
mcmaster.ca
Institutions: Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5
The Escherichia coli outer membrane phospholipid:lipid A palmitoyltransferase PagP is normally a latent enzyme, but it can be directly activated in outer membranes by lipid redistribution associated with a breach in the permeability barrier. We now demonstrate that a lipid A myristate deficiency in an E. coli O157:H7 msbB mutant constitutively activates PagP in outer membranes. The lipid A myristate deficiency is associated with hydrophobic antibiotic sensitivity and, unexpectedly, with serum sensitivity, which resulted from O-antigen polysaccharide absence due to a cytoplasmically determined truncation at the R3 core oligosaccharide's first outer core glucose unit. Mutational inactivation of pagP in the myristate-deficient lipid A background aggravated the hydrophobic antibiotic sensitivity as a result of losing a partially compensatory increase in lipid A palmitoylation, while simultaneously restoring serum resistance and O-antigen attachment to intact lipopolysaccharide. Complementation with either wild-type pagP or catalytically inactive pagPSer77Ala alleles restored the R3 core truncation. However, the intact lipopolysaccharide was preserved after complementation with an internal deletion pagP5-14 allele, which mostly eliminates a periplasmic amphipathic a-helical domain, but fully supports cell surface lipid A palmitoylation. Our findings indicate that activation of PagP not only triggers lipid A palmitoylation in the outer membrane, but also separately truncates the R3 core oligosaccharide in the cytoplasm. We discuss the implication that PagP might function as an apical sensory transducer, which can be activated by a breach in the outer membrane permeability barrier
Escherichia coli O157:H7, core oligosaccharide, outer membrane, Lipid A palmitoylation, PagP
Structure type: oligomer
Location inside paper: p.4339, scheme 2
Compound class: core oligosaccharide
Contained glycoepitopes: IEDB_120354,IEDB_123890,IEDB_130650,IEDB_130659,IEDB_135394,IEDB_140088,IEDB_141807,IEDB_150908,IEDB_151531,IEDB_2189047
Methods: 13C NMR, 1H NMR, NMR-2D, SDS-PAGE, TLC, 31P NMR, ESI-MS, acid hydrolysis, GC, composition analysis, NMR-1D, genetic methods, biochemical methods, immunoblotting, hydrazinolysis
Biological activity: antibiotic sensitivity assay, serum resistance assay
Biosynthesis and genetic data: genetic data
Comments, role: O-deacylated LPS.
3D data: 3D data
Related record ID(s): 22731, 23276
NCBI Taxonomy refs (TaxIDs): 83334
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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