テトラヌクレオソームのX線構造とそのクロマチン繊維への影響
Thomas Schalch1, Sylwia Duda, David F Sargent
1ETH Zürich, Institute for Molecular Biology and Biophysics, ETH-Hönggerberg, CH-8093 Zürich, Switzerland.
Nature
|July 8, 2005
まとめ
テトラヌクレオソームの結晶構造は,リンク器DNAがジグザグ状のパターンを形成し,クロマチンの繊維組織のための2つのスタートヘリックスモデルをサポートしており,1つのスタートソレノイドではありません.
科学分野:
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
- 遺伝学 遺伝学とは
背景:
- ユカリオットDNAは,核細胞から成るクロマチンの繊維に編成されています.
- クロマチンの高階構造は,DNAの複製,転写,修復に不可欠である.
- 染色体繊維内の核細胞組織の基本的側面については,依然として議論されている.
研究 の 目的:
- 染色体繊維内の核細胞の高階構造を決定する.
- クロマチン繊維における核細胞の配置に関する論争を解決するために.
- クロマチン組織のための高解像度の構造モデルを提供すること.
主な方法:
- 9 Åの解像度でオリゴヌクレオソーム (テトラヌクレオソーム) の結晶構造の決定.
- 既知の核細胞核構造を用いた分子置換.
- 連続した繊維構造を構築するためのコンピューティング・モデリング.
主要な成果:
- 結晶構造は,2つのスタートヘリクスを切り離し,核素核のスタック間のリンク DNA がジグザグする.
- 観察されたDNA経路は,単発ソレノイドヘリックスモデルと相容れない.
- リンカーDNAの長さは,核細胞核内の伸縮によって収納されるようです.
- モデル化された連続繊維はクロスリンカーモデルに似ており,ポリモルフな核細胞間インターフェースを示唆しています.
結論:
- この研究は,クロマチンの繊維組織のための高解像度の構造的基礎を提供します.
- この発見は,クロマチン構造のソレノイドモデルよりも2つのスタートヘリックスモデルを支持する.
- 核細胞核の伸縮は,リンク器DNAの長さの変化に対応するメカニズムである可能性が高い.
関連する概念動画
02:33The Nucleosome
DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
02:33The Nucleosome
DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
01:19The Nucleosome
Human DNA is almost two meters long. However, it is compressed inside a tiny nucleus measuring only a few microns in diameter. To make this degree of compaction possible, DNA is organized into several sequential levels so that it can fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This...
In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This...
01:32Chromatin Packaging
Each human somatic cell contains 6 billion base pairs of DNA. Each base pair is 0.34 nm long, meaning each diploid cell contains a staggering 2 meters of DNA. This long DNA strand is packed inside a nucleus measuring only 10-20 microns in diameter with the help of specialized DNA-binding proteins called histones. Together they form a compact DNA-protein complex called chromatin. The chromatin is further compacted into higher-order structures. The highest level of compaction is achieved during...