Studying the interaction between gyrase and DNA using magnetic tweezers
Studying the interaction between gyrase and DNA using magnetic tweezers
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DOI：
10.1007/s11434-012-5420-8
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发表时间：
2012-09
影响因子：
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通讯作者：
Zhiqiang Zhang;Yu-Ru Liu;P. Xie;Wei Li;Shuoxing Dou;Pengye Wang
中科院分区：
文献类型：
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作者：
Zhiqiang Zhang;Yu-Ru Liu;P. Xie;Wei Li;Shuoxing Dou;Pengye Wang
大肠杆菌的DNA旋转酶在该微生物的生命中起着重要的作用。它是所有拓扑异构酶中唯一的，因为它能够将负超螺旋引入DNA。本文研究了E.使用磁镊将粘多糖聚合酶与DNA结合。结果表明，在缺乏ATP的情况下，促旋酶与G和T片段的结合较弱。0.7pN的拉伸力可逐渐破坏结合，而5.9pN的拉伸力则直接破坏结合，高浓度的诺氟沙星可增强促旋酶与两个片段的结合，使它们适应5.9pN的拉伸力。DNA促旋酶减少了plectonemic尺寸，这是由细菌酶，而不是由拉力。此外，它对正超螺旋和负超螺旋有不同的亲和力。促旋酶与DNA解离的时间分布呈双指数形式。本文提出了一个模型来解释这种分布，并与其他模型的结果进行比较。
The DNA gyrase ofEscherichia coliplays an essential role in the life of this microorganism. It is unique among all topoisomerases because of its ability to introduce negative supercoils into DNA. This study investigated the single molecular interaction ofE. coligyrase with DNA using magnetic tweezers. The results showed that, in the absence of ATP, gyrase weakly binds the G and T segments. The stretched force of 0.7 pN can gradually destroy the binding, whereas that of 5.9 pN directly destroys it. Addition of high concentrations of norfloxacin enhances gyrase binding to both segments, making them adapt to 5.9 pN. DNA gyrase reduces the plectonemic dimension, which was determined by the bacterial enzyme and not by the pull force. Moreover, it has different affinities for positive supercoils, which it prefers, and negative supercoils. The time distribution of the dissociation of gyrase from DNA has a double-exponential form. We herein propose a model to explain this distribution and compare the results with those of other models.