首页|Supercoiled DNA Minicircles under Double-strand Breaks

Supercoiled DNA Minicircles under Double-strand Breaks

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Understanding how supercoiled DNA releases intramolecular stress is essential for its functional realization.However,the molecular mechanism underlying the relaxation process remains insufficiently explored.Here we employed MD simulations based on the oxDNA2 model to investigate the relaxation process of a 336-base pair supercoiled minicircular DNA under double-strand breaks with two fixed endpoints.Our sim-ulations show that the conformational changes in the DNA occur continuously,with intramolecular stress release happening abruptly only when the DNA chain traverses the breakage site.The relaxation process is influenced not only by the separation distance between the fixed ends but al-so their angle.Importantly,we observe an inhibitory effect on the relaxation characterized by small angles,where short terminal loops impede DNA conformational adjustments,preserving the supercoiled structure.These findings elucidate the intricate interplay between DNA conforma-tional change,DNA motion and intramolecular stress release,shedding light on the mechanisms governing the relaxation of supercoiled DNA at the molecular level.

Supercoiled DNADNA minicircleDNA relaxationoxDNA modelMD simulation

Ye-Peng Qiao、Chun-Lai Ren

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National Laboratory of Solid State Microstructures and Department of Physics,Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China

National Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of China

122742121234710212174184

2024

高分子科学(英文版)
中国化学会 中国科学院化学研究所

高分子科学(英文版)

CSTPCD
影响因子:0.721
ISSN:0256-7679
年,卷(期):2024.42(9)