Feng Yihong, Hashiya Fumitaka, Hidaka Kumi, Sugiyama Hiroshi, Endo Masayuki
Department of Chemistry, Graduate School of Science, Kyoto University, Yoshida-ushinomiyacho, Sakyo-ku, Kyoto, 606-8501, Japan.
present address: Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
Chemistry. 2020 Nov 26;26(66):15282-15289. doi: 10.1002/chem.202003071. Epub 2020 Oct 19.
The nucleosome is one of the most fundamental units involved in gene expression and consequent cell development, differentiation, and expression of cell functions. We report here a method to place reconstituted nucleosomes into a DNA origami frame for direct observation using high-speed atomic-force microscopy (HS-AFM). By using this method, multiple nucleosomes can be incorporated into a DNA origami frame and real-time movement of nucleosomes can be visualized. The arrangement and conformation of nucleosomes and the distance between two nucleosomes can be designed and controlled. In addition, four nucleosomes can be placed in a DNA frame. Multiple nucleosomes were well accessible in each conformation. Dynamic movement of the individual nucleosomes were precisely monitored in the DNA frame, and their assembly and interaction were directly observed. Neither mica surface modification nor chemical fixation of nucleosomes is used in this method, meaning that the DNA frame not only holds nucleosomes, but also retains their natural state. This method offers a promising platform for investigating nucleosome interactions and for studying chromatin structure.
核小体是参与基因表达以及随之而来的细胞发育、分化和细胞功能表达的最基本单位之一。我们在此报告一种将重组核小体置于DNA折纸框架中，以便使用高速原子力显微镜（HS-AFM）进行直接观察的方法。通过使用这种方法，可以将多个核小体整合到DNA折纸框架中，并可视化核小体的实时运动。核小体的排列和构象以及两个核小体之间的距离可以进行设计和控制。此外，四个核小体可以放置在一个DNA框架中。在每种构象中，多个核小体都易于接近。在DNA框架中精确监测了单个核小体的动态运动，并直接观察到了它们的组装和相互作用。该方法既不使用云母表面修饰，也不使用核小体的化学固定，这意味着DNA框架不仅能容纳核小体，还能保持它们的自然状态。该方法为研究核小体相互作用和染色质结构提供了一个有前景的平台。
