Lipoprotein DolP supports proper folding of BamA in the bacterial outer membrane promoting fitness upon envelope stress

Elife. 2021 Apr 13:10:e67817. doi: 10.7554/eLife.67817.


In Proteobacteria, integral outer membrane proteins (OMPs) are crucial for the maintenance of the envelope permeability barrier to some antibiotics and detergents. In Enterobacteria, envelope stress caused by unfolded OMPs activates the sigmaE (σE) transcriptional response. σE upregulates OMP biogenesis factors, including the β-barrel assembly machinery (BAM) that catalyses OMP folding. Here we report that DolP (formerly YraP), a σE-upregulated and poorly understood outer membrane lipoprotein, is crucial for fitness in cells that undergo envelope stress. We demonstrate that DolP interacts with the BAM complex by associating with outer membrane-assembled BamA. We provide evidence that DolP is important for proper folding of BamA that overaccumulates in the outer membrane, thus supporting OMP biogenesis and envelope integrity. Notably, mid-cell recruitment of DolP had been linked to regulation of septal peptidoglycan remodelling by an unknown mechanism. We now reveal that, during envelope stress, DolP loses its association with the mid-cell, thereby suggesting a mechanistic link between envelope stress caused by impaired OMP biogenesis and the regulation of a late step of cell division.

Keywords: BAM; DolP; E. coli; Envelope stress; OMPs; Outer membrane biogenesis; YraP; infectious disease; microbiology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Outer Membrane / physiology*
  • Bacterial Outer Membrane Proteins / genetics*
  • Bacterial Outer Membrane Proteins / metabolism
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / genetics*
  • Escherichia coli Proteins / metabolism
  • Genetic Fitness
  • Lipoproteins / genetics*
  • Lipoproteins / metabolism
  • Protein Folding


  • Bacterial Outer Membrane Proteins
  • BamA protein, E coli
  • Escherichia coli Proteins
  • Lipoproteins