基因组 H2A-H2B 基因组 H2A-H2B 基因组 H2A-H2B 基因组 基因组 H2A-H2B 基因组 H2A-H2B 基因组 H2A-H2B 基因组 H2A-H2B 基因组 H2A-H2B 基因组 H2A-H2B 基因组
Maria Hondele1, Tobias Stuwe, Markus Hassler
1Department of Physiological Chemistry, Butenandt Institute and LMU Biomedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, Butenandtstrasse 5, 81377 Munich, Germany.
Nature
|May 24, 2013
概括
促进染色体转录 (FACT) 复杂结构揭示了它如何结合H2A-H2B组织蛋白. 这种机制解释了FACT如何重组核体,增强DNA转录,复制和修复过程.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 促进染色体转录 (FACT) 是一个至关重要的基因质伴侣.
- 实际上,FACT重组了核体,用于DNA转录,复制和修复.
- 在此之前,FACT H2A-H2B 识别的结构基础是未知的.
研究的目的:
- 阐明FACT与H2A-H2B组 histone二次体相互作用的结构基础.
- 了解FACT结合如何影响核细胞结构和DNA可访问性.
- 为了确定FACT异构化域的结构.
主要方法:
- 用X射线晶体学来确定Spt16M (一个FACT组件) 与H2A-H2B.的结构.
- 生物化学和体内测试以验证结构发现并分析基因素相互作用.
- 对FACT异构化域的结构分析.
主要成果:
- 揭示了与H2A-H2B异体聚合物结合的FACT护卫子域Spt16M的晶体结构.
- 在Spt16M中发现了一种新的"U-turn"图案,该图案与H2A-H2B基因组二次体相互作用.
- 证明FACT结合通过重组组素-DNA接触来促进核细胞"呼吸".
结论:
- 确定的结构提供了高分辨率的洞察力,了解FACT的基本监护功能.
- FACT的H2A-H2B识别机制解释了它在核细胞重组中的作用.
- 这项工作揭示了FACT如何促进需要核细胞重塑的酶的活动.
相关概念视频
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...
02:10The 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...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
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...
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...