English

Kinky DNA in solution: Small angle scattering study of a nucleosome positioning sequence

Biological Physics 2018-11-07 v1 Statistical Mechanics Biomolecules

Abstract

DNA is a flexible molecule, but the degree of its flexibility is subject to debate. The commonly-accepted persistence length of lp500l_p \approx 500\,\AA\ is inconsistent with recent studies on short-chain DNA that show much greater flexibility but do not probe its origin. We have performed X-ray and neutron small-angle scattering on a short DNA sequence containing a strong nucleosome positioning element, and analyzed the results using a modified Kratky-Porod model to determine possible conformations. Our results support a hypothesis from Crick and Klug in 1975 that some DNA sequences in solution can have sharp kinks, potentially resolving the discrepancy. Our conclusions are supported by measurements on a radiation-damaged sample, where single-strand breaks lead to increased flexibility and by an analysis of data from another sequence, which does not have kinks, but where our method can detect a locally enhanced flexibility due to an ATAT-domain.

Keywords

Cite

@article{arxiv.1809.09335,
  title  = {Kinky DNA in solution: Small angle scattering study of a nucleosome positioning sequence},
  author = {Torben Schindler and Adrián González and Ramachandran Boopathi and Marta Marty Roda and Lorena Romero-Santacreu and Andrew Wildes and Lionel Porcar and Anne Martel and Nikos Theodorakopoulos and Santiago Cuesta-López and Dimitar Angelov and Tobias Unruh and Michel Peyrard},
  journal= {arXiv preprint arXiv:1809.09335},
  year   = {2018}
}

Comments

24 pages, 10 figures

R2 v1 2026-06-23T04:17:26.758Z