TY - JOUR
T1 - The gain-of-function allele bamAE470K bypasses the essential requirement for BamD in β-barrel outer membrane protein assembly
AU - Har, Elizabeth M.
AU - Gupta, Meera
AU - Wühr, Martin
AU - Silhavy, Thomas J.
N1 - Funding Information:
ACKNOWLEDGMENTS. We thank former and current members of the T.J.S and M.W. laboratories for helpful discussions and editing of the manuscript and thank Lillia Ryazanova for technical assistance. The research performed for this study was supported by the National Institute of General Medical Sciences of the NIH under Grants R35-GM128813 (to M.W.), R35-GM118024 (to T.J.S.), and R01-GM034821 (to T.J.S.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. This work was also supported by the Lewis–Sigler collaboration fund.
Publisher Copyright:
© 2020 National Academy of Sciences. All rights reserved.
PY - 2020/8/4
Y1 - 2020/8/4
N2 - 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, bamAE470K, that bypasses the requirement for BamD. Although bamD::kan bamAE470K 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.
AB - 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, bamAE470K, that bypasses the requirement for BamD. Although bamD::kan bamAE470K 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.
KW - Bam complex
KW - Omp assembly
KW - Outer membrane biogenesis
UR - http://www.scopus.com/inward/record.url?scp=85089166010&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85089166010&partnerID=8YFLogxK
U2 - 10.1073/pnas.2007696117
DO - 10.1073/pnas.2007696117
M3 - Article
C2 - 32675245
AN - SCOPUS:85089166010
SN - 0027-8424
VL - 117
SP - 18737
EP - 18743
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 31
ER -