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-Structure paper
Title | Cryo-electron microscopy structure of the H3-H4 octasome: A nucleosome-like particle without histones H2A and H2B. |
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Journal, issue, pages | Proc Natl Acad Sci U S A, Vol. 119, Issue 45, Page e2206542119, Year 2022 |
Publish date | Nov 8, 2022 |
Authors | Kayo Nozawa / Yoshimasa Takizawa / Leonidas Pierrakeas / Chizuru Sogawa-Fujiwara / Kazumi Saikusa / Satoko Akashi / Ed Luk / Hitoshi Kurumizaka / |
PubMed Abstract | The canonical nucleosome, which represents the major packaging unit of eukaryotic chromatin, has an octameric core composed of two histone H2A-H2B and H3-H4 dimers with ∼147 base pairs (bp) of DNA ...The canonical nucleosome, which represents the major packaging unit of eukaryotic chromatin, has an octameric core composed of two histone H2A-H2B and H3-H4 dimers with ∼147 base pairs (bp) of DNA wrapped around it. Non-nucleosomal particles with alternative histone stoichiometries and DNA wrapping configurations have been found, and they could profoundly influence genome architecture and function. Using cryo-electron microscopy, we solved the structure of the H3-H4 octasome, a nucleosome-like particle with a di-tetrameric core consisting exclusively of the H3 and H4 histones. The core is wrapped by ∼120 bp of DNA in 1.5 negative superhelical turns, forming two stacked disks that are connected by a H4-H4' four-helix bundle. Three conformations corresponding to alternative interdisk angles were observed, indicating the flexibility of the H3-H4 octasome structure. In vivo crosslinking experiments detected histone-histone interactions consistent with the H3-H4 octasome model, suggesting that H3-H4 octasomes or related structural features exist in cells. |
External links | Proc Natl Acad Sci U S A / PubMed:36322721 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.63 - 4.3 Å |
Structure data | EMDB-33010, PDB-7x57: EMDB-33011, PDB-7x58: EMDB-33991, PDB-7yoz: |
Source |
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Keywords | DNA BINDING PROTEIN/DNA / subnucleosome / NUCLEAR PROTEIN / DNA BINDING PROTEIN-DNA complex / DNA BINDING PROTEIN |