7D69

Cryo-EM structure of the nucleosome containing Giardia histones

7D69 の概要

• エントリーDOI: 10.2210/pdb7d69/pdb
• EMDBエントリー: 30591
• 分子名称: Histone H3, Histone H4, Histone H2B, ... (6 entities in total)
• 機能のキーワード: nucleosome, chromatin, histone, giardia lamblia, nuclear protein
• 由来する生物種: Giardia intestinalis; 詳細
• タンパク質・核酸の鎖数: 10
• 化学式量合計: 203790.25

構造登録者

Sato, S.,Takizawa, Y.,Kurumizaka, H. (登録日: 2020-09-29, 公開日: 2021-09-08, 最終更新日: 2025-07-02)

主引用文献

Sato, S.,Takizawa, Y.,Hoshikawa, F.,Dacher, M.,Tanaka, H.,Tachiwana, H.,Kujirai, T.,Iikura, Y.,Ho, C.H.,Adachi, N.,Patwal, I.,Flaus, A.,Kurumizaka, H.
Cryo-EM structure of the nucleosome core particle containing Giardia lamblia histones.
Nucleic Acids Res., 49:8934-8946, 2021

PubMed Abstract: Giardia lamblia is a pathogenic unicellular eukaryotic parasite that causes giardiasis. Its genome encodes the canonical histones H2A, H2B, H3, and H4, which share low amino acid sequence identity with their human orthologues. We determined the structure of the G. lamblia nucleosome core particle (NCP) at 3.6 Å resolution by cryo-electron microscopy. G. lamblia histones form a characteristic NCP, in which the visible 125 base-pair region of the DNA is wrapped in a left-handed supercoil. The acidic patch on the G. lamblia octamer is deeper, due to an insertion extending the H2B α1 helix and L1 loop, and thus cannot bind the LANA acidic patch binding peptide. The DNA and histone regions near the DNA entry-exit sites could not be assigned, suggesting that these regions are asymmetrically flexible in the G. lamblia NCP. Characterization by thermal unfolding in solution revealed that both the H2A-H2B and DNA association with the G. lamblia H3-H4 were weaker than those for human H3-H4. These results demonstrate the uniformity of the histone octamer as the organizing platform for eukaryotic chromatin, but also illustrate the unrecognized capability for large scale sequence variations that enable the adaptability of histone octamer surfaces and confer internal stability.

PubMed: 34352093
DOI: 10.1093/nar/gkab644

実験手法

ELECTRON MICROSCOPY (3.57 Å)