DNA as a one-dimensional chiral material: Application to the structural transition between B form and Z form

Abstract

A dynamical model is presented for chiral change in DNA molecules. The model is an extension of the conventional elastic model which incorporates the structure of base pairs and uses a spinor representation for the DNA configuration together with a gauge principle. Motivated by a recent experiment reporting chiral transitions between right-handed B-DNA and left-handed Z-DNA [M. Lee, et. al., Proc. Natl. Acad. Sci. (USA) 107, 4985 (2010)], we analyze the free energy for the particular case of linear DNA with an externally applied torque. The model shows that there exists, at low temperature, a rapid structural change depending on the torque exerted on the DNA, which causes switching in B and Z domain sizes. This can explain the frequent switches of DNA extension observed in experiments.

7 pages, 5 figures

References in corpus (3)

• Thermal Denaturation of Fluctuating DNA Driven by Bending Entropy
• Discontinuities at the DNA supercoiling transition
• Coupling between denaturation and chain conformations in DNA: stretching, bending, torsion and finite size effects

Cited by in corpus (2)

• DNA as a one-dimensional chiral material. II. Dynamics of the structural transition between B form and Z form
• Mechanical response to tension and torque of molecular chains via statistically interacting particles associated with extension, contraction, twist, and supercoiling