不对称的手对手转位和核细胞导航的机械模型由CMG形酶
Fritz Nagae1,2,3, Yutaka Murata1, Masataka Yamauchi1
1Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.
Nature communications
|November 21, 2025
概括
CMG螺旋酶使用不同的DNA结合状态进行定向复制. 像Csm3/Tof1和FACT这样的蛋白质复合体有助于导航核体并保持复制叉的完整性.
科学领域:
- 分子生物学分子生物学
- 生物化学 生化学
- 结构生物学 结构生物学
背景情况:
- 细胞DNA复制依赖于CMG螺旋酶来解DNA和导航核细胞.
- 对于CMG的过程性转移和核细胞相互作用的精确机制尚未完全理解.
研究的目的:
- 阐明CMG酶转位和DNA解的机制.
- 了解CMG如何在复制过程中导航核细胞障碍.
- 调查Csm3/Tof1,RPA和FACT在复制保真性和效率中的作用.
主要方法:
- 粗粒度分子动力学模拟. 粗粒度分子动力学模拟.
- 模拟CMG螺旋酶的ATP驱动的结构转换.
- 模拟与核细胞,Csm3/Tof1,RPA和FACT的相互作用.
主要成果:
- 在四个ssDNA结合状态中的不对称旋转转换驱动CMG转位和解.
- Csm3/Tof1通过抑制回溯增强了过程性;RPA减轻了滞后链堵塞.
- Csm3/Tof1促进部分核细胞解,而FACT降低了障碍物,并防止异常的基因组转移.
结论:
- CMG利用不同的ssDNA结合状态进行定向复制和解.
- 蛋白质因素在维持复制的稳定性和过程性方面发挥着至关重要的,独特的作用.
- 这项研究揭示了复原体是如何协调螺旋酶活动,核细胞导航和基因组管理的.
相关概念视频
Nucleosome Remodeling
10.7K
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
10.7K
The Movement of Organelles and Vesicles
6.0K
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
6.0K
DNA Helicases
23.8K
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...
23.8K
Forces Acting on Chromosomes
3.8K
During mitosis, chromosome movements occur through the interplay of multiple piconewton level forces. In prometaphase, these forces help in chromosome assembly or congression at the equatorial plane, eventually leading to their alignment at the metaphase plate. The forces acting on the chromosomes are space and time-dependent; therefore, they vary with the position of the chromosomes as the cell progresses through mitosis.
Microtubules and motor proteins exert two types of forces on...
Microtubules and motor proteins exert two types of forces on...
3.8K
Mechanical Protein Functions
5.5K
Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force.
5.5K
Chromatin Packaging
21.2K
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order...
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order...
21.2K


