相关实验视频
Updated: Jul 26, 2025

11:53
Substrate Generation for Endonucleases of CRISPR/Cas Systems
Published on: September 8, 2012
27.4K
在Cas4/1双核酶活动中,可以在I-G型CRISPR-Cas系统中实现预空间器成熟和定向集成
Yukti Dhingra1, Dipali G Sashital1
1Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA.
bioRxiv : the preprint server for biology
|June 19, 2023
概括
在CRISPR-Cas系统中,Cas4/1融合蛋白用于高效的DNA适应. 这种双重功能酶处理DNA间隔器并确保正确的整合,增强宿主对外来DNA的免疫力.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
背景情况:
- 克里斯普尔-卡斯系统在原核生物中提供适应性免疫力.
- 间隔器获取是CRISPR适应的一个关键步骤,由Cas1-Cas2复合体介导.
- Cas4内核酶通常需要用于功能间隔器获取,选择和处理DNA目标.
研究的目的:
- 研究一种新型I-G Cas4/1融合蛋白在CRISPR适应中的作用.
- 阐明Cas4和Cas1领域的核酶活动和金属离子需求.
- 了解这种融合蛋白如何促进预空间处理和定向集成.
主要方法:
- 生物化学测试以描述Cas4/1融合中的核酶和整合酶活动.
- 对Cas4和Cas1酶功能的金属离子依赖性的分析.
- 在体外实验中评估CRISPR阵列中的预空间处理和集成.
主要成果:
- 确定了一种I-G型Cas4/1融合与核分解活性Cas1域.
- Cas1 作为一个整合酶和一个序列独立的核酶,处理前空间的非PAM端.
- Cas4在PAM端执行特定序列的分离,确保定向集成.
- 卡斯4和卡斯1表现出不同的金属离子偏好 (卡斯4的Mn2+,卡斯1的Mg2+).
结论:
- Cas4/1融合蛋白具有双核酶活动,使其能够自主成熟.
- 这种融合通过消除对额外因素的需求,简化了适应模块.
- 独特的酶功能和金属离子要求确保将间隔器定向整合到CRISPR阵列中,加强宿主免疫.
相关概念视频
CRISPR and crRNAs
17.1K
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...
17.1K
CRISPR/Cas9 Genome Editing
78
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...
78
CRISPR
52.5K
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...
52.5K
The Antiviral System of Bacteria and Archaea: CRISPR
62
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...
62
Homologous Recombination
50.7K
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...
50.7K
Restarting Stalled Replication Forks
5.8K
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart,...
5.8K

