包装的结构基础是莫洛尼小鼠白血病病毒的二元基因组
Victoria D'Souza1, Michael F Summers
1Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21250, USA.
Nature
|October 1, 2004
概括
复原病毒使用结构开关机制包装两个RNA基因组. 分化暴露了RNA元素,使核体 (NC) 蛋白质能够通过高亲和度的结合来有效地包装基因组.
科学领域:
- 分子生物学分子生物学
- 病毒学 病毒学
- 结构生物学 结构生物学
背景情况:
- 逆转录病毒需要两个基因组RNA拷贝进行复制,因此需要特定的包装机制.
- 多蛋白的核体 (NC) 域对于RNA二分化和封装都至关重要.
- 在基因组包装中RNA二分化和NC结合之间的相互作用仍然不完全理解.
研究的目的:
- 阐明逆转录病毒RNA二元化促进基因组包装的结构机制.
- 研究Psi-RNA包装信号在介导NC结合和基因组选择中的作用.
主要方法:
- 摩洛尼小鼠白血病病毒 (MoMuLV) Psi-RNA包装信号的结构分析.
- 生物化学测试以确定NC与单体和二元RNA的结合亲和力.
- 进行X射线晶体学以确定NC-RNA复合物的结构.
主要成果:
- MoMuLV Psi-RNA的二元化诱导了基配对中的注册表转移,暴露了特定的UCUG元素.
- 这些暴露的UCUG元素以高亲和力 (Kd = 75 +/- 12 nM) 结合NC蛋白.
- 该结构揭示了NC的关节与核心封装RNA段的序列和结构特定的结合.
结论:
- 一个结构性的RNA开关机制控制着逆转录病毒基因组封装.
- 蛋白质结合部位被蒙蔽在单体RNA中,并在二分化后被揭示出来,从而促进NC结合.
- 这种机制确保了双胞胎基因组的选择性包装,这对于逆转录病毒复制至关重要.
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