Transport of torsional stress in DNA
Transport of torsional stress in DNA
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DOI：
10.1073/pnas.96.25.14342
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发表时间：
1999-12-07
影响因子：
11.1
通讯作者：
Nelson, P
中科院分区：
文献类型：
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作者：
Nelson, P
众所周知，转录可以在DNA中诱导扭转应力，影响邻近基因的活性，甚至诱导DNA双链的结构转变。长期以来，人们一直认为，产生显著的扭应力需要DNA被锚定，形成一个有限的拓扑域，因为否则它几乎可以绕着自己的轴自由旋转。然而，以前对旋转阻力的估计忽略了螺旋主干中小的自然弯曲的作用。我们展示了这些弯曲如何使阻力比先前估计的增加几千倍，即使在线性非锚定DNA中也允许显著的扭转应力。该模型有助于解释DNA转录引起的结构转变的几个令人费解的实验结果。
It is well known that transcription can induce torsional stress in DNA, affecting the activity of nearby genes or even inducing structural transitions in the DNA duplex. It has long been assumed that the generation of significant torsional stress requires the DNA to be anchored, forming a limited topological domain, because otherwise it would spin almost freely about its axis. Previous estimates of the rotational drag have, however, neglected the role of small natural bends in the helix backbone. We show how these bends can increase the drag several thousandfold relative to prior estimates, allowing significant torsional stress even in linear unanchored DNA. The model helps explain several puzzling experimental results on structural transitions induced by transcription of DNA.