Fast dynamics of supercoiled DNA revealed by single-molecule experiments
Fast dynamics of supercoiled DNA revealed by single-molecule experiments
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DOI：
10.1073/pnas.0700333104
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发表时间：
2007-07-17
影响因子：
11.1
通讯作者：
Dekker, Nynke H.
中科院分区：
文献类型：
--
作者：
Crut, Aurlien;Koster, Daniel A.;Dekker, Nynke H.
超卷曲DNA的动力学在涉及DNA超卷曲的转录和复制等多种细胞过程中起着重要作用。我们提出的实验通过测量单个DNA分子对张力或扭转突然变化的内在反应来增强我们对这些动力学的理解。观察到的动力学可以用准静态模型精确地描述，而不依赖于分子中最初存在的超卷曲程度。特别是，动力学不受连续去除元素素的影响。这些结果设定了一个流体动力学阻力的上限，从而为裸DNA的动力学提供了定量基线。
The dynamics of supercoiled DNA play an important role in various cellular processes such as transcription and replication that involve DNA supercoiling. We present experiments that enhance our understanding of these dynamics by measuring the intrinsic response of single DNA molecules to sudden changes in tension or torsion. The observed dynamics can be accurately described by quasistatic models, independent of the degree of supercoiling initially present in the molecules. In particular, the dynamics are not affected by the continuous removal of the plectonemes. These results set an upper bound on the hydrodynamic drag opposing plectoneme removal, and thus provide a quantitative baseline for the dynamics of bare DNA.