通过H-NS蛋白来解开细菌染色质组织,使用双重DNA操纵来解开
Remus T Dame1, Maarten C Noom, Gijs J L Wuite
1Department of Physics and Astronomy and Laser Centre, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands. gwuite@nat.vu.nl
Nature
|November 17, 2006
概括
类似希斯的核结构蛋白 (H-NS) 动态地桥接着DNA分子,组织细菌核. 这项研究揭示了H-NS.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 基因组学就是基因组学.
背景情况:
- 原核生物和真核生物利用DNA桥梁蛋白来调节基因和结构组织.
- 细菌核体,一个复杂的结构,是由非特定的DNA桥梁蛋白形成的,如H-NS,LRP和SMC蛋白.
- 了解非特异性DNA-蛋白相互作用的机械和分子细节仍然具有挑战性.
研究的目的:
- 研究核相关蛋白H-NS.的动态组织和DNA结合特性.
- 阐明H-NS在细菌核密封和可访问性中的作用.
- 建立一种新的实验方法来研究蛋白质介导的DNA-DNA相互作用.
主要方法:
- 开发了一种双双刀的光学仪器,用于独立操纵两个DNA分子.
- 动力力谱学的应用,以分析非特异性DNA结合蛋白.
- 系统地调查与DNA的基因组状核结构蛋白 (H-NS) 相互作用.
主要成果:
- 证明H-NS在两个DNA分子之间动态组织,与DNA螺旋曲线对齐.
- 使用动力力谱法确定了H-NS-DNA相互作用的能量场景.
- 提供了关于细菌核体的动态压缩和可访问性的见解.
结论:
- 在细菌核体的动态组织和紧缩中,H-NS起着至关重要的作用.
- 开发的光学笔技术为研究DNA桥接蛋白和复杂的DNA相互作用提供了一个多功能平台.
- 这些发现有助于理解细菌基因组的组织和细胞过程的可访问性.
相关概念视频
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...
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.
02:05Duplication of Chromatin Structure
The process of chromosome duplication during cell division requires genome-wide disruption and re-assembly of chromatin. The chromatin structure must be accurately inherited, reassembled, and maintained in the daughter cells to ensure lineage propagation.
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
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...
01:24Nucleoid
The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. Unlike eukaryotic cells, prokaryotes lack a membrane-bound nucleus, and the nucleoid facilitates the organization and accessibility of the genetic material within this constraint. The DNA in most bacteria and archaea exists as a single, circular, double-stranded molecule that is highly compacted through supercoiling and interactions with...