@article{oai:repo.qst.go.jp:00081798,
 author = {Ishida, Hisashi and Kono, Hidetoshi and Hisashi, Ishida and Hidetoshi, Kono},
 issue = {7},
 journal = {Proceedings of the National Academy of Sciences of the United States of America},
 month = {Feb},
 note = {Torsional stress has a significant impact on the structure and stability of the nucleosome.  RNA polymerase imposes torsional stress on the DNA in chromatin and unwraps the DNA from the nucleosome to access the genetic information encoded in the DNA.  To understand how the torsional stress affects the stability of the nucleosome, we examined the unwraping of the outer superhelical turn of the nucleosomal DNA under torsional stress with all-atom molecular dynamics simulations.  The free energies for unwrapping the DNA indicate that positive stress that overtwists DNA facilitates asymmetric unwrapping of the DNA while negative stress that undertwists DNA does not.  Under positive stress, DNA was straightened and rigid, which facilitated a large-scale asymmetric unwrapping of the DNA without a large extension of the DNA in which one end of the DNA was disconnected from H3 and H2A/H2B while the other end of the DNA stably remained wrapped.  Under negative stress, the DNA became more bendable and flexible, which facilitated the binding of the unwrapped DNA to the octamer in a stable state.  Consequently, we conclude that the torsion stress has a significant impact on the affinity of the DNA and the octamer through the inherent dynamic nature of the DNA: bendability and flexibility and can drastically change chromatin structure.},
 title = {Torsional stress can regulate the unwrapping of two outer half superhelical turns of nucleosomal DNA},
 volume = {118},
 year = {2021}
}