Methods for exerting and measuring forces on single molecules have revolutionized the
study of the physics of biology. However, it is often the case that biological processes involve …

Over the past two decades, measurements on individual stretched and twisted DNA
molecules have helped define the basic elastic properties of the double helix and enabled …

RNA plays myriad roles in the transmission and regulation of genetic information that are
fundamentally constrained by its mechanical properties, including the elasticity and …

Type IIA topoisomerases are essential DNA processing enzymes that must robustly and
reliably relax DNA torsional stress. While cellular processes constantly create varying …

Twisting a DNA molecule held under constant tension is accompanied by a transition from a
linear to a plectonemic DNA configuration, in which part of the applied twist is absorbed in a …

The well-established single-molecule force-spectroscopy techniques have recently been
complemented by methods that can measure torque and twist directly, notably magnetic …

Recent single-molecule experiments have observed that formation of a plectonemically
supercoiled region in a stretched, twisted DNA proceeds via abrupt formation of a small …

We present a free energy model for structural transitions of the DNA double helix driven by
tensile and torsional stress. Our model is coarse grained and is based on semiflexible …

DNA under torsional strain undergoes a buckling transition that is the fundamental step in
plectoneme nucleation and supercoil dynamics, which are critical for the processing of …

While undergoing structural deformation, DNA experiences changes in the interactions
between its internal base pairs, presenting challenges to conventional elastic methods. To …