A lipoprotein/β-barrel complex monitors lipopolysaccharide integrity transducing information across the outer membrane.
Lipoprotein RcsF is the OM component of the Rcs envelope stress response. RcsF exists in complexes with β-barrel proteins (OMPs) allowing it to adopt a transmembrane orientation with a lipidated N-terminal domain on the cell surface and a periplasmic C-terminal domain. Here we report that mutations that remove BamE or alter a residue in the RcsF trans-lumen domain specifically prevent assembly of the interlocked complexes without inactivating either RcsF or the OMP. Using these mutations we demonstrate that these RcsF/OMP complexes are required for sensing OM outer leaflet stress. Using mutations that alter the positively charged surface-exposed domain, we show that RcsF monitors lateral interactions between lipopolysaccharide (LPS) molecules. When these interactions are disrupted by cationic antimicrobial peptides, or by the loss of negatively charged phosphate groups on the LPS molecule, this information is transduced to the RcsF C-terminal signaling domain located in the periplasm to activate the stress response.
Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Princeton, United States.
Anna
0000-0002-2238-8849
A
Konovalova
Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Princeton, United States.
Angela M
AM
Mitchell
Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Princeton, United States.
Thomas J
0000-0001-7672-5153
TJ
Silhavy
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000502:physiology*; D004252:DNA Mutational Analysis; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism*; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D008070:Lipopolysaccharides; D050505:Mutant Proteins; C078611:rcsF protein, E coli
Bam complex; CAMP; E. coli; infectious disease; membrane biogenesis; microbiology; polymyxin B; signal transduction; surface exposed lipoprotein