Sld3CBD-Cdc45关于Cdc45在DNA复制过程中为CMG复合体形成的招募的结构见解
Hao Li1, Izumi Ishizaki1, Koji Kato1,2
1Graduate School of Life Science, Hokkaido University, Sapporo, Japan.
eLife
|September 8, 2025
概括
这项研究揭示了Sld3蛋白如何调节DNA复制过程中Cdc45-MCM-GINS (CMG) 螺旋酶复合物的形成. 它显示Sld3与Cdc45结合,并在解DNA时分离,澄清了CMG复合体的调节.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 启动DNA复制需要在复制起源处组装Cdc45-MCM-GINS (CMG) 酶.
- 启动因子Sld3,与Sld7一起,在招募Cdc45和GINS形成CMG复合体方面发挥着至关重要的作用.
- 目前尚不完全了解Sld3调节CMG复合物形成的精确机制.
研究的目的:
- 阐明CMG复合体形成的Sld3介导调节的结构基础和机制.
- 将Sld3 Cdc45结合域 (Sld3CBD) 的结构与Cdc45.5复合呈现出来.
- 在CMG组装过程中调查Sld3,Cdc45,GINS和MCM之间的相互作用.
主要方法:
- 进行X射线晶体学以确定Sld3CBD-Cdc45复合物的结构.
- 突变分析以评估Sld3-Cdc45相互作用的重要性.
- 生物化学试验,包括粒子大小分析和DNA结合试验.
- 模拟Sld3CBD-CMG复合体和Cdc45-MCM二次体.
主要成果:
- Sld3CBD-Cdc45的晶体结构揭示了它们结合所必需的特定相互作用和形状变化.
- 突变分析证实了Sld3CBD-Cdc45相互作用的可变性.
- 结构建模表明,Sld3CBD,GINS和MCM与Cdc45上的不同位点结合,允许Sld7-Sld3在CMG形成之前与Cdc45-MCM保持关联.
- 一项DNA结合试验表明,在未绕的单链DNA片段的存在下,Sld7-Sld3与CMG复合物分离.
结论:
- 通过其结合域,Sld3直接与Cdc45相互作用,影响CMG复合组合.
- Sld7-Sld3复合体充当支架,与Cdc45-MCM保持关联,直到CMG形成完成.
- 从CMG中解离Sld7-Sld3与未绕的单链DNA的存在有关,这表明Sld7-Sld3在复制启动或进展中起着调节作用.
- 这些发现为管理CMG复合体形成和Sld3.3调节的分子机制提供了关键的见解.
关键词:
启动DNA复制的开始美国大肠杆菌 (E. coli).K. 马克西安纳斯 (K. marxianus) 是一个古老的植物.它们中的一种是S. cerevisiae.开花的酵母酵母是什么意思它们是真核生物 (eukaryotes).启动因子 Sld3 开始因子 Sld3分子生物物理学分子生物物理学招聘 Cdc45 的工作人员.结构生物学结构生物学更多相关视频
07:37Author Spotlight: Unraveling the Dynamics of Eukaryotic DNA Replication Through Single-Molecule Visualization
Published on: September 27, 2024
2.4K
08:53Strand-Specific Analysis of Proteins at Replicating DNA Strands by Enrichment and Sequencing of Protein-Associated Nascent DNA Method
Published on: May 2, 2025
921
相关概念视频
02:38S-Cdk Initiates DNA Replication
5.3K
The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of...
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of...
5.3K
02:37Restarting Stalled Replication Forks
6.3K
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,...
6.3K
02:15M-Cdk Drives Transition Into Mitosis
6.3K
Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
6.3K
00:55DNA Helicases
23.9K
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...
23.9K
03:01The Replisome
38.1K
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
38.1K
02:36DNA Damage can Stall the Cell Cycle
10.0K
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
10.0K