T4菌原体组合和原料合成的结构基础
Xiang Feng1, Michelle M Spiering2, Ruda de Luna Almeida Santos1
1Department of Structural Biology, Van Andel Institute, Grand Rapids, MI, USA.
Nature communications
|July 20, 2023
概括
由gp41螺旋酶和gp61原酶组成的T4菌原体通过DNA诱导的螺旋酶的形状变化组装在一起. 这一过程揭示了原酶如何结合并启动DNA复制的RNA原始合成.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 病毒学 病毒学
背景情况:
- T4细菌原体对于DNA复制至关重要,它将gp41化酶的DNA解与gp61原酶的RNA原体合成相结合.
- 精确的T4原体组装机制和RNA原体长度的确定仍然在很大程度上是未知的.
研究的目的:
- 阐明T4原体组合和激活的结构基础.
- 了解gp61原酶如何与gp41基酶相互作用以启动原料合成.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来捕获T4原体组装中间体的快照.
- 结构分析的重点是gp41酶在DNA结合和原酶招募时的构造变化.
主要成果:
- T4 gp41螺旋酶存在于一个开放的螺旋,通过剪刀般的运动通过单链DNA (ssDNA) 结合过渡到一个封闭的,活跃的环.
- 酶激活暴露了一个疏水的表面,它招募了gp61原酶.
- gp61原酶以双重方式结合gp41六合体,涉及其N-终端和C-终端域与单独的gp41头二次体之间的相互作用.
结论:
- 该研究揭示了T4原体组装的详细机制,由DNA介导的酶激活和构造变化驱动.
- 这些发现提供了对酶与酶的双分结合模式的洞察,这对于启动RNA原始酶合成至关重要.
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