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Updated: Dec 14, 2025
Deciphering Molecular Mechanism of Histone Assembly by DNA Curtain Technique
Published on: March 9, 2022
Molecular mechanism of histone variant H2A.B on stability and assembly of nucleosome and chromatin structures
Junhui Peng1,2, Chuang Yuan1, Xinfan Hua1
1MOE Key Laboratory for Membraneless Organelles & Cellular Dynamics, National Science Center for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China.
Background:
H2A.B, the most divergent histone variant of H2A, can significantly modulate nucleosome and chromatin structures. However, the related structural details and the underlying mechanism remain elusive to date. In this work, we built atomic models of the H2A.B-containing nucleosome core particle (NCP), chromatosome, and chromatin fiber. Multiscale modeling including all-atom molecular dynamics and coarse-grained simulations were then carried out for these systems.
Results:
It is found that sequence differences at the C-terminal tail, the docking domain, and the L2 loop, between H2A.B and H2A are directly responsible for the DNA unwrapping in the H2A.B NCP, whereas the N-terminus of H2A.B may somewhat compensate for the aforementioned unwrapping effect. The assembly of the H2A.B NCP is more difficult than that of the H2A NCP. H2A.B may also modulate the interactions of H1 with both the NCP and the linker DNA and could further affect the higher-order structure of the chromatin fiber.
Conclusions:
The results agree with the experimental results and may shed new light on the biological function of H2A.B. Multiscale modeling may be a valuable tool for investigating structure and dynamics of the nucleosome and the chromatin induced by various histone variants.
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