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Updated: Jun 19, 2026
08:48
Stretching Short Sequences of DNA with Constant Force Axial Optical Tweezers
Published on: October 13, 2011
Structural transitions and elasticity from torque measurements on DNA
Zev Bryant1, Michael D Stone, Jeff Gore
1Department of Molecular and Cell Biology, Department of Physics, Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA.
Nature
|July 18, 2003
Summary
Researchers measured torque and twist in DNA, revealing new insights into its mechanical properties. This work advances our understanding of DNA mechanics and its role in cellular processes.
Area of Science:
- Biophysics
- Molecular Biology
- Polymer Physics
Background:
- Understanding DNA's elastic properties is crucial for cellular processes like replication and transcription.
- Previous studies focused on force and extension, but torque effects remained unmeasured in micromanipulation experiments.
Purpose of the Study:
- To directly measure torque as a function of twist in stretched DNA molecules.
- To characterize DNA's twist elasticity, torsional modulus, and torque-induced structural transitions.
Main Methods:
- Micromanipulation experiments measuring torque and twist in stretched DNA.
- Utilizing submicrometre beads as calibrated loads to measure torsional strain.
Main Results:
- Direct measurement of DNA's torque-twist relationship.
- Determined a torsional modulus approximately 40% higher than previously accepted values.
- Characterized torque-induced structural transitions and established a framework for enzyme assays.
Conclusions:
- This study provides a comprehensive understanding of DNA mechanics, including torsional properties.
- The findings enable new assays for DNA-dependent enzymes and the development of novel DNA-based nanomachines.
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