Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA.
Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA.
Biochem Biophys Res Commun. 2019 Oct 8;518(1):178-182. doi: 10.1016/j.bbrc.2019.08.027. Epub 2019 Aug 14.
Nonstructural protein 1 (NS1) is a multifunctional virulence factor of influenza virus. The effector domain (ED) of influenza viruses is capable of binding to a variety of host factors, however, the molecular basis of the interactions remains to be investigated. The isolated NS1-ED exists in equilibrium between the monomer and homodimer. Although the structural diversity of the dimer interface has been well-characterized, limited information is available regarding the internal conformational heterogeneity of the monomeric NS1-ED. Here, we present the solution NMR structure of the NS1-ED W187R of the 1918 influenza A virus, which caused the "Spanish flu." Structural plasticity is an essential property to understand the molecular mechanism by which NS1-ED interacts with multiple host proteins. Structural comparison with the NS1-ED from influenza A/Udorn/1972 (Ud) strain revealed a similar overall structure but a distinct conformational variation and flexibility. Our results suggest that conformational flexibility of the NS1-ED might differ depending on the influenza strain.
非结构蛋白 1（NS1）是流感病毒的一种多功能毒力因子。流感病毒的效应结构域（ED）能够与多种宿主因子结合，但相互作用的分子基础仍有待研究。分离的 NS1-ED 存在于单体和同源二聚体之间的平衡中。尽管二聚体界面的结构多样性已经得到很好的描述，但关于单体 NS1-ED 的内部构象异质性的信息有限。在这里，我们展示了导致“西班牙流感”的 1918 年流感 A 病毒的 NS1-ED W187R 的溶液 NMR 结构。结构可塑性是理解 NS1-ED 与多种宿主蛋白相互作用的分子机制的必要性质。与流感 A/Udorn/1972（Ud）株的 NS1-ED 的结构比较显示出相似的整体结构，但构象变化和灵活性明显不同。我们的结果表明，NS1-ED 的构象灵活性可能因流感株而异。
