来自Mycobacterium tuberculosis的Ku的寡合化促进了DNA突触
Sayma Zahid1, Sonia Baconnais2, Henrietta Smith3
1Leicester Institute for Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK.
Nature communications
|November 26, 2025
概括
结核菌菌 Ku 蛋白质通过通过非同类末端连接修复DNA损伤,对生存至关重要. 结构研究揭示了它的DNA结合机制,这对细菌弹性和潜在的治疗点至关重要.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 结核病 (TB) 是由Mycobacterium tuberculosis (Mtb) 引起的,影响全球四分之一的人口.
- Mtb的弹性与其高效的DNA修复机制有关,特别是非同类末端连接 (NHEJ).
- Ku 蛋白和 LigD 酶是 Mtb 中 NHEJ 的关键介质.
研究的目的:
- 研究Ku蛋白在破坏DNA的条件下对Mtb生存的重要作用.
- 阐明 Mtb.中Ku-DNA相互作用的结构和机制基础.
- 了解Ku在招募其他DNA修复因子 (如LigD) 的作用.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定Ku-Mtb的高分辨率结构.
- 生物物理分析以研究Ku-DNA结合和丝的形成.
- 位点定向突变发生,以评估关键残留物对细菌活力的影响.
主要成果:
- 当接触到破坏DNA的物质时,Ku对于Mtb的生存至关重要.
- 冷EM揭示了Apo和DNA结合的Ku-Mtb同质体的高分辨率结构.
- Ku在DNA结合时形成一个延伸的蛋白丝,其中的特定残留物对丝形成和DNA突触至关重要.
- 这些关键残留物中的突变显著损害了细菌的生存能力.
- 提出了一个模型,Ku的C端调节DNA结合,加载和LigD招募.
结论:
- 库蛋白在Mtb的DNA双链断裂修复途径中发挥着关键的,必不可少的作用.
- 对Ku-DNA相互作用的结构洞察力为细菌DNA修复提供了机械的理解.
- 这些发现为开发针对DNA修复途径的新型抗结核病疗法提供了潜在的途径.
更多相关视频
相关概念视频
DNA Topoisomerases
34.7K
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. ...
34.7K
Translesion DNA Polymerases
11.0K
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...
11.0K
Mismatch Repair
6.3K
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
6.3K
Mismatch Repair
43.5K
Overview
43.5K
Homologous Recombination
62.5K
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...
62.5K
Covalently Linked Protein Regulators
8.6K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
These groups modify specific amino acids in a protein....
8.6K


