人类凝聚素-NIPBL-DNA复合体的冷-EM结构
Zhubing Shi1, Haishan Gao1, Xiao-Chen Bai2,3
1Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
概括
人类凝聚素是一种环形的ATPase,通过捕获DNA来组织基因组. 通过加载器NIPBL,Cryo-EM揭示了它的结构,解释了DNA循环挤出和姐妹染色体凝聚机制.
科学领域:
- 分子生物学
- 结构生物学
- 遗传学
背景情况:
- 凝聚素是一种环形ATPase,对基因组组织至关重要.
- 它通过捕获DNA来挤出DNA循环并调解姐妹染色体凝聚力.
- 凝聚素的DNA交易的确切机制尚不清楚.
研究的目的:
- 确定与载体NIPBL和DNA结合的人类凝聚素的结构.
- 阐明DNA被凝聚素捕获和激活的机制.
主要方法:
- 中等分辨率的冷电子显微镜 (冷EM).
- 人类凝聚素-NIPBL-DNA复合物的结构分析.
主要成果:
- 凝聚素和NIPBL形成了广泛的相互作用,形成了DNA捕获的中心道.
- 一个72个基对的DNA段被困在凝聚素-NIPBL复合体内.
- NIPBL和DNA协同激活凝聚蛋白的ATP酶头域和ATP结合.
- Cohesin的链域采用"开放式冲洗器"形状,与STAG1子单元对接.
结论:
- 确定的结构解释了NIPBL和DNA对凝聚素的协同激活.
- 提供了关键的洞察力 DNA 被凝聚复合物的机制.
- 在基因组组织和姐妹染色体凝聚力中的凝聚作用的理解.
相关概念视频
Cohesins
5.3K
Cohesin protein complexes are a molecular glue that holds two sister chromatids together. They play an important role both in mitosis and meiosis. In mitosis, all cohesin complexes present on the chromosomes are removed before the start of the anaphase stage.
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of...
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of...
5.3K
Chromatin Packaging
20.9K
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...
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...
20.9K
Chromatin Packaging
18.6K
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...
18.6K
The Nucleosome
3.5K
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...
3.5K
The Nucleosome
18.1K
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...
18.1K
Nucleoid
651
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...
651


