一个紧的病毒IRES翻译下游的开放阅读框架.
bioRxiv : the preprint server for biology
|June 4, 2025
概括
研究人员在巨型病毒E 3'未翻译区域中发现了一个小的IV型内部核糖体进入点 (IRES). 这种RNA结构能够实现上限独立的翻译,但其水平低于以前已知的IRES.
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:
- 型肝炎C病毒 (HCV) 和其他RNA病毒利用其5'未翻译区域 (UTRs) 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元素形成复杂的三级结构,直接与核糖体接触.
研究的目的:
- 在病毒基因组中使用生物信息学方法识别新型IV型IRESRNA.
- 为了描述新发现的,异常位置和大小的IV型IRES在巨型病毒E (MeV-E) 中.
主要方法:
- 病毒基因组的生物信息分析以检测潜在的IV型IRES元素.
- 使用冷电子显微镜 (cryo-EM) 确定MeV-E 3' IRES的二次和三维结构.
- 功能性测试用于评估MeV-E 3' IRES的翻译启动活动.
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具有较小的尺寸和确认的二次结构,与核糖体相互作用.
- 这种IRES可以促进下游开放阅读框架的翻译启动,尽管与5'IRES相比效率降低.
结论:
- MeV-E 3'IRES是一种新的,紧的IV型IRES变体,可能适用于下游病毒蛋白的调节表达.
- 在IRES元素中的结构变化允许精确调整翻译级别,如MeV-E 3' IRES所示.
- 这一发现为病毒RNA的结构多样性及其在调节基因表达中的作用提供了洞察力.
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