Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea.
Department of Physics and Astronomy, National Center for Creative Research Initiatives, Seoul National University, Seoul 08826, South Korea.
Cell Chem Biol. 2019 Apr 18;26(4):502-511.e3. doi: 10.1016/j.chembiol.2018.12.003. Epub 2019 Jan 31.
Topoisomerase II cleaves DNA at preferred sequences with different efficiencies; however, the mechanism of cleavage site selection is not known. Here we used single-molecule fluorescence assays that monitor several critical steps of DNA-topoisomerase II interactions, including binding/dissociation, bending/straightening, and cleavage/religation, and reveal that the cleavage site is selected mainly during the bending step. Furthermore, despite the sensitivity of the bending rate to the DNA sequence, it is not an intrinsic property of the DNA itself. Rather, it is determined by protein-DNA interactions.
拓扑异构酶 II 在不同效率下在优选序列处切割 DNA；然而，切割位点选择的机制尚不清楚。在这里，我们使用单分子荧光分析方法来监测 DNA-拓扑异构酶 II 相互作用的几个关键步骤，包括结合/解离、弯曲/变直和切割/连接，并揭示了切割位点主要在弯曲步骤中被选择。此外，尽管弯曲速率对 DNA 序列很敏感，但它不是 DNA 本身的固有特性。相反，它是由蛋白-DNA 相互作用决定的。
