菌体T4DNA复制复合物的功能整合:ssDNA结合蛋白 (gp32) 的多重作用
Claire S Albrecht1,2,3, Brett Israels1,2,4, Jack Maurer1,2,4
1Center for Optical, Molecular and Quantum Science, University of Oregon, Eugene, Oregon 97403.
bioRxiv : the preprint server for biology
|September 15, 2025
概括
单链DNA结合蛋白 (gp32) 调节T4菌体的DNA复制. 它的C端域 (CTDs) 是启动DNA结处蛋白质组合的关键,受DNA晶格极性影响.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 病毒学 病毒学
背景情况:
- 单链DNA结合蛋白 (gp32) 对于T4菌体DNA复制至关重要,协调复杂的子组件以实现高速和高保真DNA合成.
- Gp32蛋白与单链DNA (ssDNA) 结合,滑动和解结合,以促进复制,保护DNA免受核酶的影响,并防止二次结构的形成.
- 虽然N-终端域 (NTDs) 调解合作相互作用,但C-终端域 (CTDs) 在启动gp32-ssDNA线索组合的作用仍然不清楚.
研究的目的:
- 调查分子机制和自由能景观,控制gp32组装在ssDNA上的初始步骤.
- 阐明gp32的C终端域 (CTD) 在gp32-ssDNA丝在单链/双链DNA (ssDNA/dsDNA) 连接处核化的作用.
- 了解DNA晶格极性如何影响gp32核和ssDNA/dsDNA结处的调节相互作用.
主要方法:
- 微秒分辨率的单分子福斯特共振能量转移 (smFRET) 研究.
- 在模型ssDNA/dsDNA连接处附近,对不同长度和极性的短小氧-脱氧提米丁格子上的gp32组件的分析.
- 确定gp32集群启动的分子步骤和自由能量表面.
主要成果:
- 在ssDNA/dsDNA结处的Gp32核化机制和调节相互作用受到DNA晶格极性的影响.
- 该研究定义了分子步骤和相关的自由能量表面,参与启动gp32集群形成.
- 数据表明,CTDs在ssDNA/dsDNA结点附近定向gp32单体的模型,在核和解离过程中促进受控的,非基序特定的结合.
结论:
- 本质上有障碍的CTD在ssDNA/dsDNA结点对gp32单体的定位起着至关重要的作用,促进调节的结合.
- 格子极性是gp32核和ssDNA/dsDNA结处的调节相互作用的关键决定因素.
- 这些发现提供了关于CTD如何在菌体DNA复制过程中控制gp32光纤动态中的非基序特定结合的见解.
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