相关实验视频
Updated: Mar 14, 2026

11:53
Substrate Generation for Endonucleases of CRISPR/Cas Systems
Published on: September 8, 2012
28.1K
DNA基质的扭曲约束 冲击Cas9裂变
Michael H Räz1, Kumi Hidaka2, Shana J Sturla1
1Department of Health Sciences and Technology, ETH Zürich , Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
Journal of the American Chemical Society
|October 7, 2016
概括
对DNA的扭曲约束显著影响了Cas9的裂变. 限制非目标链降低了Cas9的效率,而限制目标链的影响最小,揭示了DNA结构
科学领域:
- 分子生物学
- 生物化学
- 结构生物学
背景情况:
- Cas9核酶是CRISPR-Cas9基因编辑系统的一个关键组成部分.
- Cas9 DNA 分裂的机制受到DNA基质特性的影响.
- 了解DNA结构如何影响Cas9活动对于优化基因编辑技术至关重要.
研究的目的:
- 研究DNA基板中的扭曲约束对Cas9核酶活性的影响.
- 要确定DNA原形生成的扭曲约束如何影响Cas9裂变效率.
- 阐明Cas9/sgRNA复合物与受约束的DNA基质分离的动态.
主要方法:
- 使用DNA原形框架制备扭曲约束和放松的DNA基板.
- 使用定量聚合酶链反应 (qPCR) 量化Cas9裂变效率.
- 使用高速原子力显微镜 (HS-AFM) 观察和描述Cas9/sgRNA复合结合和解离动态.
主要成果:
- 非目标DNA链上的扭矩约束显著降低了Cas9裂变效率.
- 目标DNA链上的扭曲约束对Cas9裂变的影响最小.
- HS-AFM揭示了来自DNA基质的Cas9/sgRNA复合物的解离动力学.
结论:
- 高度排序和扭曲约束的DNA结构可以阻碍Cas9核酶的活性.
- 扭曲应力对DNA基板的方向对Cas9裂变有不同的影响.
- 这项研究提供了对Cas9解离机制的单分子见解,并突出了DNA结构作为影响Cas9功能的因素.
相关概念视频
DNA Topoisomerases
37.0K
Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
37.0K
Single-Strand DNA Binding Proteins
17.1K
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
17.1K
DNA Helicases
24.7K
DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...
24.7K
CRISPR
58.6K
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...
58.6K
CRISPR/Cas9 Genome Editing
2.4K
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...
2.4K
Translesion DNA Polymerases
11.5K
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
11.5K

