Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale, Grenoble, France.
Angew Chem Int Ed Engl. 2016 Aug 1;55(32):9356-60. doi: 10.1002/anie.201602619. Epub 2016 Jun 6.
Measles virus RNA genomes are packaged into helical nucleocapsids (NCs), comprising thousands of nucleo-proteins (N) that bind the entire genome. N-RNA provides the template for replication and transcription by the viral polymerase and is a promising target for viral inhibition. Elucidation of mechanisms regulating this process has been severely hampered by the inability to controllably assemble NCs. Here, we demonstrate self-organization of N into NC-like particles in vitro upon addition of RNA, providing a simple and versatile tool for investigating assembly. Real-time NMR and fluorescence spectroscopy reveals biphasic assembly kinetics. Remarkably, assembly depends strongly on the RNA-sequence, with the genomic 5' end and poly-Adenine sequences assembling efficiently, while sequences such as poly-Uracil are incompetent for NC formation. This observation has important consequences for understanding the assembly process.
麻疹病毒 RNA 基因组被包装成螺旋形核衣壳（NCs），由数千个核蛋白（N）组成，这些核蛋白结合整个基因组。N-RNA 为病毒聚合酶的复制和转录提供模板，是病毒抑制的有前途的靶点。由于无法控制地组装 NCs，阐明调节该过程的机制受到了严重阻碍。在这里，我们证明了在添加 RNA 后，N 能够在体外自行组织成类似 NC 的颗粒，为研究组装提供了一种简单而通用的工具。实时 NMR 和荧光光谱揭示了两相组装动力学。值得注意的是，组装强烈依赖于 RNA 序列，基因组 5' 端和聚腺嘌呤序列有效地组装，而聚尿嘧啶等序列则不能形成 NC。这一观察结果对理解组装过程具有重要意义。
