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Updated: May 28, 2026
08:48
Stretching Short Sequences of DNA with Constant Force Axial Optical Tweezers
Published on: October 13, 2011
Underwound DNA under tension: structure, elasticity, and sequence-dependent behaviors
Maxim Y Sheinin1, Scott Forth, John F Marko
1Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.
Physical Review Letters
|October 11, 2011
Summary
DNA melting under torsion was studied at the single-molecule level. Torsionally melted DNA forms a left-handed structure and is sequence-dependent at low forces, revealing new insights into DNA mechanics.
Area of Science:
- Molecular Biology
- Biophysics
- Structural Biology
Background:
- DNA melting is crucial for cellular processes.
- Understanding DNA's response to torsion is essential.
Purpose of the Study:
- Investigate DNA melting at the single-molecule level under torsion.
- Determine structural and elastic parameters of torsionally melted DNA.
Main Methods:
- Utilized an angular optical trap.
- Directly measured force, extension, torque, and angle of DNA.
Main Results:
- Torsionally melted DNA forms a left-handed structure under moderate forces.
- Melted DNA exhibits high torsional compliance.
- At low forces, DNA melting properties are sequence-dependent.
Conclusions:
- Provides a comprehensive DNA force-torque phase diagram.
- Elucidates the structural transitions of DNA under torsional stress.
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