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在菌体λ囊体中,温度诱导的DNA密度转变与对比匹配的SANS揭示了

José Ramón Villanueva Valencia¹, Efthymios Tsimtsirakis¹, Susan Krueger²

¹Department of Experimental Medical Science and NanoLund, Lund University, Lund 22184, Sweden.

Proceedings of the National Academy of Sciences of the United States of America

|October 30, 2023

概括

病毒基因组喷射是由菌体囊体内的DNA密度过渡驱动的. 温度升高导致DNA从有序转移到无序状态,促进释放和感染.

科学领域:

结构生物学是结构生物学.
病毒学病毒学
生物物理学的生物物理.

背景情况:

病毒基因组的包装和释放对于感染至关重要.
菌体兰巴 (λ) DNA中的温度诱导的机械转换导致喷射,但其结构基础是未知的.

研究的目的:

阐明菌体 λ.中温度诱导的DNA机械转变的结构起源.
了解囊体内的DNA结构变化如何影响基因组释放动态.

主要方法:

微角中子散射 (SANS) 用于确定DNA形状因子.
微角X射线散射 (SAXS) 和冷电子显微镜 (cryo-EM) 用于初始结构参数.
使用结构输入,精确建模SANS数据.

主要成果:

揭示了菌体λ囊体内的温度依赖的DNA密度过渡.
确定了两个共存的DNA阶段:一个外围六边形有序的高密度阶段和一个核心低密度,较少有序的阶段.
在身体温度 (~37°C) 附近的核心DNA阶段观察到显著的密度和体积过渡.

结论:

DNA密度转换在体核中产生较低的能量状态,从而增加了DNA的移动性.
这种增加的移动性对于启动快速的基因组喷射到宿主细胞至关重要.
这些发现与之前对菌体中机械DNA转换的观察相一致.

关键词:

基因结构 DNA结构 DNA结构没有SANS,就没有SANS.对比匹配对比匹配的对比匹配菌体是一种菌体.病毒生物物理病毒生物物理

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