在病毒囊成熟过程中出现了一种意想不到的转折
Ilya Gertsman1, Lu Gan, Miklos Guttman
1Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
Nature
|February 11, 2009
概括
第一个菌体的体结构揭示了病毒如何扩大和成熟. 这项对HK97菌的研究提供了对双链DNA病毒外热成熟的结构基础的见解.
科学领域:
- 结构生物学 结构生物学
- 病毒学 病毒学
- 生物化学 生物化学
背景情况:
- 细菌囊体在基因组包装过程中经历了显著的构造变化.
- 成熟的菌体囊体的特征很好,但囊体结构在很大程度上是未知的.
- 囊体是囊体成熟和基因组包装的必不可少的中间体.
研究的目的:
- 为了确定HK97细菌的X射线结构procapsid (proheadII).
- 为了比较procapsid结构与成熟的HK97囊体,以了解成熟机制.
- 阐明细菌体中观察到的外热成熟过程的结构基础.
主要方法:
- 进行X射线晶体学 (3.65 Å分辨率),以确定前头II结构.
- 与之前解决的成熟HK97体结构 (3.44 Å分辨率) 的比较.
- 结晶学和/交换数据分析以确定结构变化.
主要成果:
- 介绍了双链DNA细菌 procapsid (prohead II) 的第一个原子分辨率结构.
- 鉴定出了分单元三级结构的显著差异,分别是procapsid和成熟的capsid状态.
- 发现三重轴上的关键子单元相互作用在成熟过程中保持不变,作为构造变化的链.
结论:
- 结构比较揭示了菌体囊成熟的前所未有的扩张机制.
- 观察到的三级结构变化为外热成熟过程提供了结构基础.
- 这种机制可能保留在其他双链DNA细菌菌体和相关病毒 (如疹病毒) 中.
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