English

Hairpins in the conformations of a confined polymer

Biological Physics 2018-03-26 v2 Soft Condensed Matter

Abstract

If a semiflexible polymer confined to a narrow channel bends around by 180 degrees, the polymer is said to exhibit a hairpin. The equilibrium extension statistics of the confined polymer are well understood when hairpins are vanishingly rare or when they are plentiful. Here we analyze the extension statistics in the intermediate situation via experiments with DNA coated by the protein RecA, which enhances the stiffness of the DNA molecule by approximately one order of magnitude. We find that the extension distribution is highly non-Gaussian, in good agreement with Monte Carlo simulations of confined discrete wormlike chains. We develop a simple model that qualitatively explains the form of the extension distribution. The model shows that the tail of the distribution at short extensions is determined by conformations with one hairpin.

Keywords

Cite

@article{arxiv.1611.05736,
  title  = {Hairpins in the conformations of a confined polymer},
  author = {E. Werner and A. Jain and A. Muralidhar and K. Frykholm and T. St Clere Smithe and J. Fritzsche and F. Westerlund and K. D. Dorfman and B. Mehlig},
  journal= {arXiv preprint arXiv:1611.05736},
  year   = {2018}
}

Comments

Revised version. 22 pages, 7 figures, 2 tables, supplementary material