Impact of DNA twist accumulation on progressive helical wrapping of torsionally constrained DNA.
Impact of DNA twist accumulation on progressive helical wrapping of torsionally constrained DNA.
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DOI：
10.1103/physrevlett.109.218102
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发表时间：
2012-11
影响因子：
8.6
通讯作者：
Wei Li;Peng-Ye Wang;Jie Yan;Ming Li
中科院分区：
文献类型：
--
作者：
Wei Li;Peng-Ye Wang;Jie Yan;Ming Li
DNA包裹是细胞和病毒中染色体DNA包装的重要机制。以往的研究大多是在扭转不受约束的DNA上进行的，而在体内DNA往往是在扭转约束下进行的。在这项研究中，我们扩展了以前提出的理论模型的扭曲不受约束的DNA包装的一个新的模型，包括DNA扭曲能量的贡献，影响DNA包装急剧。特别是，由于在DNA缠绕过程中的扭曲能量的积累，它预测了有限数量的DNA，可以缠绕在螺旋线轴上。新模型的预测进行了测试的单分子研究的DNA缠绕下的扭转约束，使用磁镊。理论预测和实验结果是相互一致的，并讨论了它们的影响。
DNA wrapping is an important mechanism for chromosomal DNA packaging in cells and viruses. Previous studies of DNA wrapping have been performed mostly on torsionally unconstrained DNA, while in vivo DNA is often under torsional constraint. In this study, we extend a previously proposed theoretical model for wrapping of torsionally unconstrained DNA to a new model including the contribution of DNA twist energy, which influences DNA wrapping drastically. In particular, due to accumulation of twist energy during DNA wrapping, it predicts a finite amount of DNA that can be wrapped on a helical spool. The predictions of the new model are tested by single-molecule study of DNA wrapping under torsional constraint using magnetic tweezers. The theoretical predictions and the experimental results are consistent with each other and their implications are discussed.