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Twist- and tension-mediated elastic coupling between DNA-binding proteins
Elena F Koslover1, Andrew J Spakowitz
1Biophysics Program, Stanford University, Stanford, California 94305, USA.
Physical Review Letters
|June 13, 2009
Summary
Applied tension to DNA induces elastic stresses that mediate interactions between DNA-binding proteins. This tension can optimize protein assembly, suggesting a role in tension-mediated gene regulation.
Area of Science:
- Biophysics
- Molecular Biology
- Genetics
Background:
- DNA-binding proteins play crucial roles in gene regulation.
- The mechanical properties of DNA can influence protein interactions.
- Understanding protein-DNA interactions under tension is vital for comprehending cellular processes.
Purpose of the Study:
- To investigate the effective interaction between DNA-binding proteins mediated by DNA elastic stresses under applied tension.
- To explore how DNA bending and twisting energies affect protein aggregation and coupling.
- To determine if applied tension can optimize protein assembly on DNA.
Main Methods:
- Utilized the wormlike chain model to calculate the free energy cost of DNA bending.
- Analyzed the impact of DNA twist resistance on protein coupling free energy.
- Calculated the mean first encounter time for proteins sliding along DNA.
Main Results:
- Bend deformation energy favors DNA straightening, promoting protein aggregation.
- DNA twist resistance results in damped oscillations in protein coupling free energy.
- An optimal applied tension for protein assembly was identified under certain conditions.
- Variable-range oscillatory coupling between proteins was observed.
Conclusions:
- DNA twist is a significant factor in protein interactions, even without applied torsion.
- Tension-mediated protein coupling offers a potential mechanism for gene regulation.
- Applied tension can modulate the dynamics of protein assembly on DNA.
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