DNA supercoiling, a critical signal regulating the basal expression of the lac operon in Escherichia coli

Scientific Reports
Geraldine FulcrandFenfei Leng

Abstract

Escherichia coli lac repressor (LacI) is a paradigmatic transcriptional factor that controls the expression of lacZYA in the lac operon. This tetrameric protein specifically binds to the O1, O2 and O3 operators of the lac operon and forms a DNA loop to repress transcription from the adjacent lac promoter. In this article, we demonstrate that upon binding to the O1 and O2 operators at their native positions LacI constrains three (-) supercoils within the 401-bp DNA loop of the lac promoter and forms a topological barrier. The stability of LacI-mediated DNA topological barriers is directly proportional to its DNA binding affinity. However, we find that DNA supercoiling modulates the basal expression from the lac operon in E. coli. Our results are consistent with the hypothesis that LacI functions as a topological barrier to constrain free, unconstrained (-) supercoils within the 401-bp DNA loop of the lac promoter. These constrained (-) supercoils enhance LacI's DNA-binding affinity and thereby the repression of the promoter. Thus, LacI binding is superhelically modulated to control the expression of lacZYA in the lac operon under varying growth conditions.

References

Jan 1, 1988·Cell Biophysics·H V WesterhoffM Gellert
Jun 1, 1989·Proceedings of the National Academy of Sciences of the United States of America·C S Waddell, N L Craig
Jul 5, 1987·Journal of Molecular Biology·J A BorowiecJ D Gralla
Aug 14, 1972·Journal of Molecular Biology·J BeckwithR Arditti
Sep 20, 1974·Nature·J C WangS Bourgeois
Nov 1, 1984·Cell·T P Malan, W R McClure
Nov 1, 1983·Proceedings of the National Academy of Sciences of the United States of America·J R SadlerJ L Betz
Jan 1, 1983·Cold Spring Harbor Symposia on Quantitative Biology·R Kim, S H Kim
Jun 1, 1995·Journal of Bacteriology·P R JensenH V Westerhoff
Apr 1, 1996·Molecular Microbiology·M van WorkumH V Westerhoff
Feb 1, 1996·Journal of Molecular Graphics·W HumphreyK Schulten
Mar 1, 1996·Genes to Cells : Devoted to Molecular & Cellular Mechanisms·T InadaH Aiba
Dec 16, 1997·Proceedings of the National Academy of Sciences of the United States of America·K KimataH Aiba
Aug 14, 1998·Molecular Microbiology·B Müller-Hill
Oct 16, 1999·The Journal of Biological Chemistry·C M Falcon, K S Matthews
Jun 1, 2000·Proceedings of the National Academy of Sciences of the United States of America·K A Datsenko, B L Wanner
Jul 26, 2003·The Journal of Biological Chemistry·Mofang LiuSusan Garges
Jan 17, 2004·Structure·Alexander BalaeffKlaus Schulten
Nov 4, 2004·The Journal of Biological Chemistry·Vera A Stupina, James C Wang
Mar 10, 2006·Journal of Molecular Biology·Szabolcs SemseySankar Adhya
Dec 1, 1966·Proceedings of the National Academy of Sciences of the United States of America·W Gilbert, B Müller-Hill
Mar 23, 2007·Proceedings of the National Academy of Sciences of the United States of America·Thomas KuhlmanTerence Hwa
Jul 12, 2007·Proceedings of the National Academy of Sciences of the United States of America·Aurélien CrutNynke H Dekker
Oct 6, 2007·Critical Reviews in Biochemistry and Molecular Biology·Patricia L Foster
Aug 20, 2009·Current Pharmaceutical Biotechnology·Haowei WangDavid Dunlap
Feb 27, 2010·Nucleic Acids Research·Bo ChenFenfei Leng
Nov 30, 2011·Proceedings of the National Academy of Sciences of the United States of America·Fenfei LengDavid D Dunlap
Sep 18, 2012·Science·M T J van LoenhoutC Dekker
Jan 12, 2013·PloS One·Samuel HornusEric Fourmentin
Mar 19, 2013·Journal of Molecular Biology·Mitchell Lewis
Oct 17, 2014·Proceedings of the National Academy of Sciences of the United States of America·Yue DingLaura Finzi

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Citations

Oct 16, 2016·Biophysics Reviews·Agnes NoySarah A Harris
Oct 27, 2016·PloS One·Lauren S MogilL James Maher
Jan 25, 2018·Nucleic Acids Research·Yan YanDavid Dunlap
Mar 15, 2018·Nucleic Acids Research·Yan YanLaura Finzi
Jul 12, 2017·The Journal of Biological Chemistry·Xiaoduo ZhiFenfei Leng
Dec 31, 2016·Biophysics Reviews·Agnes NoySarah A Harris
May 17, 2017·Biophysics Reviews·Charles J Dorman, Matthew J Dorman
May 17, 2017·Biophysics Reviews·Laura Finzi, David Dunlap
Jan 16, 2020·Bioengineering·Johanna HausjellOliver Spadiut
May 17, 2017·Biophysics Reviews·Charles J Dorman, Matthew J Dorman
Mar 16, 2019·Scientific Reports·Samuel M D OliveiraAndre S Ribeiro
May 20, 2018·Physical Review. E·Céline BardeManoel Manghi
Dec 4, 2021·Physical Review Letters·Purba ChatterjeeSangjin Kim

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Methods Mentioned

BETA
atomic force microscopy
AFM
PCR
electrophoresis
Assay

Software Mentioned

ImageJ
Image Analysis
VMD
GraphiteLifeExplorer
KODAK 1D Image
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