Department of Chemistry, New York University, New York, NY 10003, USA.
Photon Sciences, National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973, USA.
Cell Chem Biol. 2017 Nov 16;24(11):1401-1406.e2. doi: 10.1016/j.chembiol.2017.08.018. Epub 2017 Oct 5.
There is an increasing appreciation for structural diversity of DNA that is of interest to both DNA nanotechnology and basic biology. Here, we have explored how DNA responds to torsional stress by building on a previously reported two-turn DNA tensegrity triangle and demonstrating that we could introduce an extra nucleotide pair (np) into the original sequence without affecting assembly and crystallization. The extra np imposes a significant torsional stress, which is accommodated by global changes throughout the B-DNA duplex and the DNA lattice. The work reveals a near-atomic structure of naked DNA under a torsional stress of approximately 14%, and thus provides an example of DNA distortions that occur without a requirement for either an external energy source or the free energy available from protein or drug binding.
人们越来越关注对 DNA 结构多样性的认识，这既与 DNA 纳米技术有关，也与基础生物学有关。在这里，我们通过构建之前报道的双转角 DNA 张拉整体三角形，探索了 DNA 如何响应扭转应力，并证明我们可以在不影响组装和结晶的情况下在原始序列中引入额外的一对核苷酸（np）。额外的 np 会产生很大的扭转应力，这会通过整个 B-DNA 双链体和 DNA 晶格的全局变化来适应。这项工作揭示了在大约 14%的扭转应力下裸露 DNA 的近原子结构，因此提供了一个没有外部能源或蛋白质或药物结合自由能要求的 DNA 扭曲的例子。
