气候变化领域集成服务门户(CCPortal): Torsional stress can regulate the unwrapping of two outer half superhelical turns of nucleosomal DNA

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DOI	10.1073/pnas.2020452118
	Torsional stress can regulate the unwrapping of two outer half superhelical turns of nucleosomal DNA
	Ishida H.; Kono H.
发表日期	2021
ISSN	00278424
卷号	118 期号:7
英文摘要	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 unwrapping of two half superhelical turns of nucleosomal DNA from either end of the 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 a large-scale asymmetric unwrapping of the DNA without a large extension of the DNA. During the unwrapping, one end of the DNA was dissociated from H3 and H2A-H2B, while the other end of the DNA stably remained wrapped. The detailed analysis indicates that this asymmetric dissociation is facilitated by the geometry and bendability of the DNA under positive stress. The geometry stabilized the interaction between the major groove of the twisted DNA and the H3 αN-helix, and the straightened DNA destabilized the interaction with H2A-H2B. 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 torsional stress has a significant impact on the affinity of the DNA and the octamer through the inherent nature of the DNA and can change the accessibility of regulatory proteins. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Nucleosome \| unwrapping \| DNA \| bendability \| torsional stress
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180627
作者单位	Molecular Modeling and Simulation Group, Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology, Kizugawa, Kyoto, 619-0215, Japan
推荐引用方式 GB/T 7714	Ishida H.,Kono H.. Torsional stress can regulate the unwrapping of two outer half superhelical turns of nucleosomal DNA[J],2021,118(7).
APA	Ishida H.,&Kono H..(2021).Torsional stress can regulate the unwrapping of two outer half superhelical turns of nucleosomal DNA.Proceedings of the National Academy of Sciences of the United States of America,118(7).
MLA	Ishida H.,et al."Torsional stress can regulate the unwrapping of two outer half superhelical turns of nucleosomal DNA".Proceedings of the National Academy of Sciences of the United States of America 118.7(2021).