胡桃坂計画研究代表による成果がiScience誌に掲載されました!

A method for cryo-EM analysis of eukaryotic nucleosomes reconstituted in bacterial cells

Cheng-Han Ho, Yuki Kobayashi, Mitsuo Ogasawara, Yoshimasa Takizawa, Hitoshi Kurumizaka

Abstract
Conventional methods for preparing nucleosomes are time-consuming and technically demanding. In the present study, we extended the approach of generating nucleosomes in E. coli by the co-expression of all four histones, allowing nucleosomes to be assembled in cells. The bacterially reconstituted nucleosomes can be readily prepared from the E. coli cells and directly subjected to cryo-EM single particle analysis. Using this method, we obtained a 2.56 Å nucleosome structure that is highly similar to a previously reported nucleosome crystal structure, validating the use of nucleosomes formed in E. coli for cryo-EM analysis. Unexpectedly, we also discovered a non-canonical nucleosome structure, in which two hexasomes are closely packed. This system provides a robust and efficient platform for structural studies of nucleosomes and nucleosome variants, and may facilitate the discovery of chromatin architectures.

iScience, doi: 10.1016/j.isci.2025.114453. (2025)
https://www.cell.com/iscience/fulltext/S2589-0042(25)02714-2