Title | The gain-of-function allele bypasses the essential requirement for BamD in β-barrel outer membrane protein assembly. |
Publication Type | Journal Article |
Year of Publication | 2020 |
Authors | Hart, EM, Gupta, M, Wühr, M, Silhavy, TJ |
Journal | Proc Natl Acad Sci U S A |
Volume | 117 |
Issue | 31 |
Pagination | 18737-18743 |
Date Published | 2020 Aug 04 |
ISSN | 1091-6490 |
Keywords | Bacterial Outer Membrane, Bacterial Outer Membrane Proteins, Escherichia coli, Escherichia coli Proteins, Gain of Function Mutation |
Abstract | <p>The outer membrane (OM) of gram-negative bacteria confers innate resistance to toxins and antibiotics. Integral β-barrel outer membrane proteins (OMPs) function to establish and maintain the selective permeability of the OM. OMPs are assembled into the OM by the β-barrel assembly machine (BAM), which is composed of one OMP-BamA-and four lipoproteins-BamB, C, D, and E. BamB, C, and E can be removed individually with only minor effects on barrier function; however, depletion of either BamA or BamD causes a global defect in OMP assembly and results in cell death. We have identified a gain-of-function mutation, , that bypasses the requirement for BamD. Although ::kan cells exhibit growth and OM barrier defects, they assemble OMPs with surprising robustness. Our results demonstrate that BamD does not play a catalytic role in OMP assembly, but rather functions to regulate the activity of BamA.</p> |
DOI | 10.1073/pnas.2007696117 |
Alternate Journal | Proc Natl Acad Sci U S A |
PubMed ID | 32675245 |
PubMed Central ID | PMC7414184 |
Grant List | R01 GM034821 / GM / NIGMS NIH HHS / United States R35 GM118024 / GM / NIGMS NIH HHS / United States R35 GM128813 / GM / NIGMS NIH HHS / United States |