Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
J Virol. 2020 Feb 28;94(6). doi: 10.1128/JVI.01729-19.
Vesicular stomatitis virus (VSV) is an archetypical member of , viruses with a genome of negative-sense single-stranded RNA (-ssRNA). Like other viruses of this order, VSV encodes a unique polymerase, a complex of viral L (large, the enzymatic component) protein and P (phosphoprotein, a cofactor component). The L protein has a modular layout consisting of a ring-shaped core trailed by three accessory domains and requires an N-terminal segment of P (P N-terminal disordered [P]) to perform polymerase activity. To date, a binding site for P on L had not been described. In this report, we show that the connector domain of the L protein, which previously had no assigned function, binds a component of P We further show that this interaction is a positive regulator of viral RNA synthesis, and that the interfaces mediating it are conserved in other members of Finally, we show that the connector-P interaction fits well into the existing structural information of VSV L. This study represents the first functional assignment of the connector domain of a L protein. Furthermore, this study localizes P polymerase cofactor activity to specific amino acids. The functional necessity of this interaction, combined with the uniqueness of L and P proteins to the order , makes disruption of the P-connector site a potential target for developing antivirals against other negative-strand RNA viruses. Furthermore, the connector domain as an acceptor site for the P protein represents a new understanding of L protein biology.
水疱性口炎病毒（VSV）是具有负义单链 RNA（-ssRNA）基因组的典型病毒。与该目的其他病毒一样，VSV 编码一种独特的聚合酶，即病毒 L（大，酶成分）蛋白和 P（磷蛋白，辅助因子成分）蛋白的复合物。L 蛋白具有模块化布局，由环形核心组成，其后跟随三个辅助结构域，并且需要 P 的 N 端片段（P N 端无序 [P]）来发挥聚合酶活性。迄今为止，尚未描述 L 蛋白上 P 的结合位点。在本报告中，我们表明 L 蛋白的连接子结构域以前没有分配功能，它与 P 的一个组成部分结合。我们进一步表明，这种相互作用是病毒 RNA 合成的正调节剂，介导这种相互作用的界面在 目的其他成员中保守。最后，我们表明连接器-P 相互作用很好地符合 VSV L 的现有结构信息。这项研究代表了首次对 目的 L 蛋白连接子结构域进行功能分配。此外，这项研究将 P 聚合酶辅助因子活性定位到特定的氨基酸。这种相互作用的功能必要性，再加上 L 和 P 蛋白对目的的独特性，使破坏 P-连接器位点成为开发针对其他负链 RNA 病毒的抗病毒药物的潜在目标。此外，作为 P 蛋白接受位点的连接器结构域代表了对 目的 L 蛋白生物学的新认识。
