一个双晶病毒基因组使用其3'端附近的紧型IV型IRES来表达一个跨膜蛋白质
Madeline E Sherlock1, Katherine E Segar2, Jeffrey S Kieft2
1New York Structural Biology Center, New York, NY 10025, USA; Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
Cell reports
|February 12, 2026
概括
研究人员在巨型病毒E的3'未翻译区域 (UTR) 中发现了一个小的新型IV型内核糖核体入口点 (IRES).这种RNA元素能够实现独立于帽子的翻译,促进病毒蛋白的表达.
科学领域:
- 病毒学 病毒学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 许多RNA病毒,包括型肝炎病毒 (HCV),利用其5'未翻译区域 (UTR) 中的IV型内核核糖体进入点 (IRES) 来启动独立于帽的翻译.
- 这些IRES元素直接与核糖体接触,启动蛋白质合成.
研究的目的:
- 在病毒基因组中识别和描述新的IRES元素.
- 研究E (MeV-E) 大型病毒中假定IV型IRES的不寻常的基因组位置和结构特征.
主要方法:
- 生物信息同类搜索被用来识别潜在的IRES序列.
- 使用冷电子显微镜 (cryo-EM) 来确定MeV-E 3' IRES与核糖体复合的3D结构.
主要成果:
- 在MeV-E的3' UTR中发现了一个假定的IV型IRES,与典型的5' UTR位置不同.
- MeV-E 3' IRES 比许多其他 IV 型 IRES 元素要小.
- 冷EM揭示了MeV-E 3' IRES与核糖体相互作用的结构基础.
- 证明MeV-E 3' IRES可以启动翻译,尽管效率低于5' UTR IRES.
结论:
- 该MeV-E 3'IRES代表了一种新的,紧的IV型IRES,位于一个不寻常的基因组位置.
- 这个小的IRES可以方便翻译第二个开放的读取框架,可能编码了一个保存的跨膜蛋白.
- 这些发现扩大了我们对病毒翻译策略和IRES多样性的理解.
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