関連する実験動画
Updated: May 27, 2026
09:32
Deciphering High-Resolution 3D Chromatin Organization via Capture Hi-C
Published on: October 14, 2022
静音化の構造的基礎:3.0 Åの解像度でニュクレオソームを持つ複合体におけるSir3 BAHドメイン
Karim-Jean Armache1, Joseph D Garlick, Daniele Canzio
1Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA.
Science (New York, N.Y.)
|November 19, 2011
まとめ
ユカリオットの遺伝子静止は,核細胞とSir3タンパク質の相互作用に依存しています. 結晶構造は,これらの相互作用と改変が,細胞運命を決定する重要な静音化クロマチンの領域を形成する方法を明らかにします.
科学分野:
- 分子生物学は分子生物学である.
- クロマチンの生物学
- 構造生物学 構造生物学とは
背景:
- 遺伝子の静止は,真核細胞の運命を調節するために不可欠です.
- クロマチン構造は,静寂状態を維持する上で重要な役割を果たします.
- Sir3を含むサイレント・インフォメーション・レギュレータ (Sir) タンパク質は,酵母における交配型の調節に極めて重要です.
研究 の 目的:
- 酵母 Sir3 BAH ドメインの結晶構造を決定するために,核素核粒子を複合させた.
- サイレントクロマチンのドメインを生成する分子相互作用を解明する.
- 特定のヒストンの改変がサイレンシング複合体の形成にどのように影響するかを理解する.
主な方法:
- 3.0アングストームの解像度のX線結晶学.
- Sir3 BAHドメインと核細胞核粒子複合体の構造分析.
- 遺伝子の変異を観察された分子相互作用にマッピングする.
主要な成果:
- 結晶構造は,Sir3 BAHドメインと核細胞表面の間の広範な分子相互作用を明らかにしています.
- 観察された相互作用は,遺伝子サイレンシングに影響を与える数多くの文書化された遺伝子変異を説明します.
- 核体とBAHドメインの両方の構造的再編成が特定されました.
- この構造は,H4K16とH3K79の共電性改変がサイレンシング複合体の形成をどのように調節するかについての洞察を提供します.
結論:
- Sir3 BAHドメインは,ニュクレオソームと直接相互作用し,静音化クロマチンを形成する.
- 決定された構造は,遺伝子サイレンスメカニズムを理解するための分子基盤を提供します.
- ヒストンの改変は,Sir3核群複合体の形成と機能の重要な調節因子である.
関連する概念動画
02:10The Nucleosome Core Particle
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.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
01:12The Nucleosome Core Particle
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...
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
02:41Chromatin Structure Regulates pre-mRNA Processing
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
02:30siRNA - Small Interfering RNAs
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the ATP-dependent...
02:54Nucleosome Remodeling
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...