Torsional behavior of chromatin is modulated by rotational phasing of nucleosomes.

ABSTRACT: Torsionally stressed DNA plays a critical role in genome organization and regulation. While the effects of torsional stresses on naked DNA have been well studied, little is known about how these stresses propagate within chromatin and affect its organization. Here we investigate the torsional behavior of nucleosome arrays by means of Brownian dynamics simulations of a coarse-grained model of chromatin. Our simulations reveal a strong dependence of the torsional response on the rotational phase angle Ψ0 between adjacent nucleosomes. Extreme values of Ψ0 lead to asymmetric, bell-shaped extension-rotation profiles with sharp maxima shifted toward positive or negative rotations, depending on the sign of Ψ0, and to fast, irregular propagation of DNA twist. In contrast, moderate Ψ0 yield more sy

SUBMITTER: Nam GM 

PROVIDER: S-EPMC4150795 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature