title: A mutant Escherichia coli that attaches peptidoglycan to lipopolysaccharide and displays cell wall on its surface.
abstract: The lipopolysaccharide (LPS) forms the surface-exposed leaflet of the outer membrane (OM) of Gram-negative bacteria, an organelle that shields the underlying peptidoglycan (PG) cell wall. Both LPS and PG are essential cell envelope components that are synthesized independently and assembled by dedicated transenvelope multiprotein complexes. We have identified a point-mutation in the gene for O-antigen ligase (WaaL) in Escherichia coli that causes LPS to be modified with PG subunits, intersecting these two pathways. Synthesis of the PG-modified LPS (LPS*) requires ready access to the small PG precursor pool but does not weaken cell wall integrity, challenging models of precursor sequestration at PG assembly machinery. LPS* is efficiently transported to the cell surface without impairing OM function. Because LPS* contains the canonical vancomycin binding site, these surface-exposed molecules confer increased vancomycin-resistance by functioning as molecular decoys that titrate the antibiotic away from its intracellular target. This unexpected LPS glycosylation fuses two potent pathogen-associated molecular patterns (PAMPs).
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, United States.
authors.forename: Marcin
authors.initials: M
authors.lastname: Grabowicz
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.
authors.forename: Dorothee
authors.initials: D
authors.lastname: Andres
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Lebar
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.
authors.forename: Goran
authors.initials: G
authors.lastname: Malojčić
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kahne
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, United States.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Silhavy
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites; D019729:Carbon-Oxygen Ligases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002473:Cell Wall / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006031:Glycosylation; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism*; D009154:Mutation; D010457:Peptidoglycan / Q000737:chemistry / Q000378:metabolism*; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D008070:Lipopolysaccharides; D010457:Peptidoglycan; D014640:Vancomycin; D019729:Carbon-Oxygen Ligases; C571195:WaaL protein, E coli
keywords: E. coli; antibiotic resistance; cell envelope; infectious disease; lipopolysaccharide; microbiology; outer membrane; peptidoglycan; vancomycin