Hidden Markov Analysis of Nucleosome Unwrapping Under Force
Hidden Markov Analysis of Nucleosome Unwrapping Under Force
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DOI：
10.1016/j.bpj.2009.01.048
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发表时间：
2009-05-06
影响因子：
3.4
通讯作者：
van Noort, J.
中科院分区：
文献类型：
--
作者：
Kruithof, M.;van Noort, J.
DNA-蛋白质复合物的瞬时构象变化在DNA代谢中起着重要作用，但通常很难解决。单分子力谱具有跟踪此类反应的独特能力，但DNA系链端到端距离的布朗波动可能会掩盖这些事件。在这里，我们测量了力诱导的解包裹的DNA从一个单一的核小体，并显示隐马尔可夫分析，采用非线性力延伸的DNA，可以很容易地解决解包裹的事件是显着小于布朗波动。由此产生的系绳长度的概率分布被用来准确地解决轮廓长度和持久性长度的微小变化。后者被证明是直接相关的DNA弯曲角的复杂。蠕虫状链适应隐马尔可夫分析可用于任何瞬态DNA-蛋白质复合物，并提供了一个强大的方法，这些瞬态事件的调查。
Transient conformational changes of DNA-protein complexes play an important role in the DNA metabolism but are generally difficult to resolve. Single molecule force spectroscopy has the unique capability to follow such reactions but Brownian fluctuations in the end-to-end distance of a DNA tether can obscure these events. Here we measured the force-induced unwrapping of DNA from a single nucleosome and show that hidden Markov analysis, adopted for the nonlinear force-extension of DNA, can readily resolve unwrapping events that are significantly smaller than the Brownian fluctuations. The resulting probability distributions of the tether length are used to accurately resolve small changes in contour length and persistence length. The latter is shown to be directly related to the DNA bending angle of the complex. The wormlike chain-adapted hidden Markov analysis can be used for any transient DNA-protein complex and provides a robust method for the investigation of these transient events.