Supercoiling DNA Locates Mismatches.
Supercoiling DNA Locates Mismatches.
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DOI：
10.1103/physrevlett.119.147801
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发表时间：
2017-10-06
影响因子：
8.6
通讯作者：
Neuman KC
中科院分区：
文献类型：
--
作者：
Dittmore A;Brahmachari S;Takagi Y;Marko JF;Neuman KC
本文提出了一种利用磁镊超卷曲DNA检测序列缺陷的方法。该方法对数千个碱基对的DNA序列中的单个错配碱基对非常敏感。我们系统地比较了0到16个相邻错配的DNA分子，在1 M的单价盐和3.6 pN力下，结果表明，在这些条件下，单个细胞素形成并稳定地固定在缺陷上。我们使用这些测量来估计缺陷处末端环扭结的能量和程度。由此，我们计算了在生理相关条件下，在失配处钉住血小板素的相对概率。基于这一估计，我们提出DNA超卷曲可能有助于体内失配和损伤感知。
We present a method of detecting sequence defects by supercoiling DNA with magnetic tweezers. The method is sensitive to a single mismatched base pair in a DNA sequence of several thousand base pairs. We systematically compare DNA molecules with 0 to 16 adjacent mismatches at 1 M monovalent salt and 3.6 pN force and show that, under these conditions, a single plectoneme forms and is stably pinned at the defect. We use these measurements to estimate the energy and degree of end-loop kinking at defects. From this, we calculate the relative probability of plectoneme pinning at the mismatch under physiologically relevant conditions. Based on this estimate, we propose that DNA supercoiling could contribute to mismatch and damage sensing in vivo.