パラマグネティックNMRスペクトロスコーピで探査された核体内のヒストンH4尾の形状と相互作用の風景
Wenjun Sun, Olga O Lebedenko1, Nicole Gonzalez Salguero
1Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia.
Journal of the American Chemical Society
|November 9, 2023
まとめ
ヒストンのH4尾は,ダイナミックな方法で核細胞DNAと相互作用します.
科学分野:
- 分子生物学
- 生物化学
- 構造生物学
背景:
- クロマチンの基本単位である核体はDNAとヒストンタンパク質で構成されています.
- ヒストンの尾,特にH3とH4はクロマチンの構造と調節に不可欠です.
- ヒストンの尾のダイナミクスを理解することは 遺伝子発現制御の解読の鍵です
研究 の 目的:
- 核分裂体内のヒストンH4尾の構成組と相互作用を調査する.
- 先進的な生体物理学技術を用いてH4尾の正確な位置と動態をマッピングする.
主な方法:
- 溶液 核磁気共振 (NMR) スペクトロスコーピー
- スピンラベルのヒストンH3を用いたパラマグネティック・リラクゼーション・エンハンスメント (PREs)
- リコンビネント・ニュクレオソーム・コア・パーティクルを濃縮したH4で再構成する
- マイクロ秒のスケールで分子ダイナミクスシミュレーション
主要な成果:
- 実験的なPREsは,H4の尾とH3の相対的な残留物特有の近接情報を提供した.
- 分子動力学シミュレーションは,PREデータを解釈し,核細胞構造をモデル化するのに役立ちます.
- ヒストンH4尾の核素核粒子内の詳細な局所化は達成された.
結論:
- ヒストンH4尾は,ニュクレオソームDNAとのダイナミックな"ぼんやりとした"相互作用を示します.
- この相互作用は,クロマチンの凝縮と調節メカニズムに寄与する可能性があります.
- この発見により 核細胞の構造と機能の関係に関する理解が深まりました
関連する概念動画
01:12The Nucleosome Core Particle
923
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
923
01:19The Nucleosome
1.6K
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...
1.6K
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
855
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
855
01:182D NMR: Overview of Heteronuclear Correlation Techniques
192
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
192
01:15¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.1K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.1K
02:54Nucleosome Remodeling
9.2K
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
9.2K