The research paper from the Kurumizaka Lab has been published in the Journal of Biological Chemistry!

Structural basis of RNA polymerase II transcription on the histone H3-H4 octasome

Ching-Hao Ho, Kaho Nozawa, Mai Nishimura, Masahiro Oi, Tomoya Kujirai, Mitsuo Ogasawara, Hiroshi Ehara, Shun-ichi Sekine, Yoshimasa Takizawa, Hitoshi Kurumizaka

Abstract
The histone H3-H4 octasome is a nucleosome-like particle in which two DNA gyres are wrapped around each histone (H3-H4)2 tetramer disk, forming a clamshell-like configuration. In the present study, we performed in vitro RNA polymerase II (RNAPII) transcription assays with the H3-H4 octasome and found that RNAPII transcribed the H3-H4 octasome more efficiently than the nucleosome. RNAPII paused at only one position, superhelical location (SHL(-4)) in the H3-H4 octasome, in contrast to pausing at the SHL(-5), SHL(-2), and SHL(-1) positions in the nucleosome. Cryo-EM analysis revealed that two (H3-H4)2 tetramer disks are retained when the RNAPII paused at the SHL(-4) position of the H3-H4 octasome. However, when RNAPII reached the SHL(-0.5) position, five base pairs before the dyad position of the H3-H4 octasome, the proximal (H3-H4)2 tetramer was disassembled, but the distal (H3-H4)2 tetramer still remained on the DNA. Therefore, RNAPII efficiently transcribes the H3-H4 octasome by stepwise (H3-H4)2 tetramer disassembly.

Journal of Biological Chemistry, 302, 111340. doi: 10.1016/j.jbc.2026.111340. (2026)
https://www.sciencedirect.com/science/article/pii/S0021925826002103?via%3Dihub