@article{144031,
  author = {Elizabeth M. Hart and Meera Gupta and Martin W{\"u}hr and Thomas J. Silhavy},
  title = {The Synthetic Phenotype of ΔbamB ΔbamE Double Mutants Results from a Lethal Jamming of the Bam Complex by the Lipoprotein RcsF},
  abstract = { The selective permeability of the Gram-negative outer membrane (OM)<br>is maintained by integral -barrel outer membrane proteins (OMPs). The heteropentomeric<br>-barrel assembly machine (Bam) folds and inserts OMPs into the OM. Coordination<br>of the essential proteins BamA and BamD is critical for OMP assembly and<br>therefore the viability of the cell. The role of the nonessential lipoproteins BamBCE<br>has yet to be characterized; however, genetic evidence suggests that they have nonoverlapping<br>roles in OMP assembly. In this work, we quantify changes of the proteome<br>in the conditional lethal ΔbamB ΔbamE double mutant. We show that cells<br>lacking BamB and BamE have a global OMP defect that is a result of a lethal obstruction<br>of an assembly-competent Bam complex by the lipoprotein RcsF. RcsF is a<br>stress-sensing lipoprotein that is threaded through the lumen of abundant -barrel<br>OMPs by the Bam complex to expose the amino terminus on the cell surface. We<br>demonstrate that simply removing this lipoprotein corrects the severe OMP assembly<br>defect of the double mutant nearly as efficiently as a previously isolated suppressor<br>mutation in bamA. We propose that BamB and BamE play crucial, nonoverlapping<br>roles to coordinate the activities of BamA and BamD during OMP<br>biogenesis. },
  year = {2019},
  journal = {mBio},
  volume = {10},
  pages = {e00662-19},
  url = {https://mbio.asm.org/content/10/3/e00662-19/article-info},
  language = {eng},
}