Suppressor Mutations in LptF Bypass Essentiality of LptC by Forming a Six-Protein Transenvelope Bridge That Efficiently Transports Lipopolysaccharide.

ABSTRACT: Lipopolysaccharide (LPS) is an essential component of the outer membrane (OM) of many Gram-negative bacteria, providing a barrier against the entry of toxic molecules. In Escherichia coli, LPS is exported to the cell surface by seven essential proteins (LptA-G) that form a transenvelope complex. At the inner membrane, the ATP-binding cassette (ABC) transporter LptB₂FG associates with LptC to power LPS extraction from the membrane and transfer to the periplasmic LptA protein, which is in complex with the OM translocon LptDE. LptC interacts both with LptB₂FG and LptADE to mediate the formation of the transenvelope bridge and regulates the ATPase activity of LptB₂FG. A genetic screen has previously identified suppressor mutants at a residue (R212) of LptF that

SUBMITTER: Falchi FA 

PROVIDER: S-EPMC9972910 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature