基因组整合复合体的结构
Addison V Wright1, Jun-Jie Liu1,2, Gavin J Knott1
1Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
概括
Cas1-Cas2整合酶使用DNA结构,而不仅仅是序列, 将外来DNA整合到CRISPR位点. 在IHF的帮助下,这种机制确保了细菌对病毒的适应性免疫力.
科学领域:
- 分子生物学
- 微生物学
- 结构生物学
背景情况:
- 在细菌中,CRISPR-Cas系统提供了对菌体的适应性免疫力.
- Cas1-Cas2整合酶对于获得新的间隔器和将外来DNA整合到CRISPR位点至关重要.
研究的目的:
- 通过Cas1-Cas2整合酶阐明DNA整合的结构机制.
- 了解CRISPR阵列扩展过程中如何实现集成位置的选择.
主要方法:
- 用X射线结晶学来确定Cas1-Cas2-DNA复合物的结构.
- 用冷电子显微镜检测全CRISPR位点整合复合物与IHF.
主要成果:
- 晶体结构显示Cas1-Cas2与捐赠者和向DNA结合在中间状态和产物状态.
- 低温电磁结构显示了集成复合体,包括集成宿主因子 (IHF).
- 整合部位的选择是由间接的DNA序列识别和依赖序列的DNA变形决定的.
结论:
- Cas1-Cas2利用DNA结构特征,有利于重复和侧面序列变形,用于特定位置的整合.
- 通过将上游基因与Cas1接触,IHF结合会诱导激烈的DNA曲,提高整合的特异性和效率.
- 这些发现解释了由Cas1-Cas2对细菌适应性免疫的部位选择性CRISPR阵列扩展的序列依赖DNA结构识别机制.
相关概念视频
CRISPR
58.2K
Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced...
58.2K
CRISPR and crRNAs
19.3K
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
19.3K
The Antiviral System of Bacteria and Archaea: CRISPR
808
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats is a adaptive immune system found in bacteria and archaea that protects against viral infections. This system enables prokaryotic cells to identify, remember, and neutralize foreign genetic elements, primarily bacteriophages, by storing fragments of the invader’s DNA as a genetic memory.The CRISPR immune response begins during an initial infection. Cas (CRISPR-associated) proteins play a central role in this...
808
CRISPR/Cas9 Genome Editing
2.1K
The CRISPR-Cas system serves as a bacterial defense mechanism against invading genetic elements such as viruses and plasmids, forming the foundation for its adaptation as a powerful genome-editing tool. Originally discovered in prokaryotes, this system has been repurposed to revolutionize genetic engineering across a wide range of organisms, including plants, animals, and humans. The core component, Cas9, is an endonuclease derived from Streptococcus pyogenes, capable of introducing...
2.1K
Homologous Recombination
64.3K
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
64.3K
Protein Complexes with Interchangeable Parts
3.0K
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
3.0K


