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Specifically bound BZIP transcription factors modulate DNA supercoiling transitions
Johanna Hörberg1, Anna Reymer2
1Department of Chemistry and Molecular Biology, University of Gothenburg, 40530, Gothenburg, Sweden.
Scientific Reports
|November 3, 2020
Summary
DNA torsional stress impacts transcription factor binding. MafB binding alters DNA
Area of Science:
- Molecular Biology
- Biophysics
- Computational Biology
Background:
- Torsional stress on DNA regulates gene transcription.
- Transcription factors bind DNA, influencing promoter opening and nucleosome remodeling.
Purpose of the Study:
- Investigate the effect of torsional stress on DNA complexation with the human BZIP transcription factor, MafB.
- Analyze how MafB binding alters DNA's response to torsional strain.
Main Methods:
- All-atom microsecond molecular dynamics simulations.
- Torsional restraint to control DNA twist.
- Gradual over- and underwinding of DNA with and without MafB.
Main Results:
- MafB binding increases torsional rigidity of DNA steps involved in protein-DNA contacts.
- MafB undergoes conformational changes to accommodate DNA deformation while maintaining specific contacts.
- Overtwisting becomes significantly more energetically unfavorable for DNA-MafB complexes compared to free DNA.
Conclusions:
- Specifically bound BZIP factors like MafB can act as torsional stress insulators.
- This insulation modulates torsional stress propagation along chromatin.
- This mechanism may facilitate cooperative binding of other DNA-binding factors.
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