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-Structure paper
タイトル | Histone octamer rearranges to adapt to DNA unwrapping. |
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ジャーナル・号・ページ | Nat Struct Mol Biol, Vol. 25, Issue 1, Page 101-108, Year 2018 |
掲載日 | 2017年12月11日 |
著者 | Silvija Bilokapic / Mike Strauss / Mario Halic / |
PubMed 要旨 | Nucleosomes, the basic units of chromatin, package and regulate expression of eukaryotic genomes. Although the structure of the intact nucleosome is well characterized, little is known about ...Nucleosomes, the basic units of chromatin, package and regulate expression of eukaryotic genomes. Although the structure of the intact nucleosome is well characterized, little is known about structures of partially unwrapped, transient intermediates. In this study, we present nine cryo-EM structures of distinct conformations of nucleosome and subnucleosome particles. These structures show that initial DNA breathing induces conformational changes in the histone octamer, particularly in histone H3, that propagate through the nucleosome and prevent symmetrical DNA opening. Rearrangements in the H2A-H2B dimer strengthen interaction with the unwrapping DNA and promote nucleosome stability. In agreement with this, cross-linked H2A-H2B that cannot accommodate unwrapping of the DNA is not stably maintained in the nucleosome. H2A-H2B release and DNA unwrapping occur simultaneously, indicating that DNA is essential in stabilizing the dimer in the nucleosome. Our structures reveal intrinsic nucleosomal plasticity that is required for nucleosome stability and might be exploited by extrinsic protein factors. |
リンク | Nat Struct Mol Biol / PubMed:29323273 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.7 - 10.5 Å |
構造データ | EMDB-3925: EMDB-3926: EMDB-3929: EMDB-3930: EMDB-3931: |
由来 |
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キーワード | GENE REGULATION (遺伝子発現の調節) / nucleosome (ヌクレオソーム) / nucleosome breathing / hexasome |