The elastic energy of sharply bent nicked DNA

Authors

Hao Qu, University of California, Los Angeles
Chiao-Yu Tseng, University of California, Los Angeles
Yong Wang, University of Arkansas, FayettevilleFollow
Alex J. Levine, University of California, Los Angeles
Giovanni Zocchi, University of California, Los AngelesFollow

Document Type

Article

Publication Date

4-29-2010

Keywords

DNA springs, protein-DNA chimeras, biomolecules, equilibrium deformations, polymer physics

Abstract

We obtain measurements of the elastic energy of short (18–30 bp) molecules of ds DNA constrained into a sharply bent conformation, using a thermodynamic method with the DNA in solution. We consider the case where there is one nick in the ds DNA, and find that the system develops a kink at a critical torque τc≈27 pN×nm. In this regime the elastic energy is linear in the end-to-end distance (EED). For smaller torques the DNA is smoothly bent and described by the worm-like–chain energy, which is also approximately linear in the EED, but with a different slope. Thus we access both the high and low elastic energy regimes, and the transition between the two.

Citation

Qu, H., Tseng, C., Wang, Y., Levine, A. J., & Zocchi, G. (2010). The elastic energy of sharply bent nicked DNA. Physics Faculty Publications and Presentations., 90 (1), 18003. https://doi.org/https://doi.org/10.1209/0295-5075/90/18003