Ebola virus nucleoprotein (eNP) assembles into higher-ordered structures that form the viral nucleocapsid (NC) and serve as the scaffold for viral RNA synthesis. However, molecular insights into the NC assembly process are lacking. Using a hybrid approach, we characterized the NC-like assembly of eNP, identified novel regulatory elements, and described how these elements impact function. We generated a three-dimensional structure of the eNP NC-like assembly at 5.8 Å using electron cryo-microscopy and identified a new regulatory role for eNP helices α22-α23. Biochemical, biophysical, and mutational analyses revealed that inter-eNP contacts within α22-α23 are critical for viral NC assembly and regulate viral RNA synthesis. These observations suggest that the N terminus and α22-α23 of eNP function as context-dependent regulatory modules (CDRMs). Our current study provides a framework for a structural mechanism for NC-like assembly and a new therapeutic target.

中文翻译：

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埃博拉病毒核蛋白的电子低温显微镜结构揭示了核衣壳样组装的机制。

埃博拉病毒核蛋白（eNP）组装成高阶结构，形成病毒核衣壳（NC），并充当病毒RNA合成的支架。但是，缺乏对NC组装过程的分子洞察力。使用混合方法，我们表征了eNP的类似NC的组件，确定了新的调控元件，并描述了这些元件如何影响功能。我们使用电子冷冻显微镜在5.8Å处生成了eNP NC-like组件的三维结构，并确定了eNP螺旋α22-α23的新调控作用。生化，生物物理和突变分析表明，α22-α23中的eNP间接触对于病毒NC装配和调节病毒RNA合成至关重要。这些观察结果表明，eNP的N末端和α22-α23发挥了上下文相关调节模块（CDRM）的作用。