C 末端半胱氨酸在戊型肝炎病毒 ORF2 截短蛋白形成病毒样颗粒和寡聚化中的作用。

Role of the C-terminal cysteines in virus-like particle formation and oligomerization of the hepatitis E virus ORF2 truncated proteins.

机构信息

College of Basic Medicine, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China; Department of Gastroenterology, Zhongda Hospital, Southeast University, Nanjing, 210009, Jiangsu province, China.

College of Basic Medicine, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China.

出版信息

Virology. 2020 May;544:1-11. doi: 10.1016/j.virol.2020.01.011. Epub 2020 Feb 14.

DOI:10.1016/j.virol.2020.01.011

PMID:32174509

Abstract

The hepatitis E virus (HEV) ORF2 truncated recombinant proteins can self-assemble into virus-like particles (VLPs) and were used as models to investigate the HEV capsid assembly. However, the structural function of the ORF2 C-terminal domain (C52aa from aa 608 to aa 660) remains unclear. Herein, by analyzing a set of ORF2 truncated proteins expressed in Escherichia coli, we found that the highly conserved C-terminal cysteines play a crucial role in the oligomerization of the truncated ORF2 proteins and in their assembly into VLPs, through the formation of dimer-dimer disulfide bonds; and the treatment of native HEV particles with dithiothreitol (DTT) induced the disassembly of the viral capsid, suggesting that the disulfide bonding is required for stabilizing the native HEV capsid. The present study sheds light on the structural role of the C-terminal region of the HEV capsid protein and contributes to the full understating of the viral capsid assembly process.

摘要

戊型肝炎病毒（HEV）ORF2 截短重组蛋白可以自我组装成病毒样颗粒（VLPs），并被用作研究 HEV 衣壳组装的模型。然而，ORF2 C 末端结构域（aa608 到 aa660 的 52 个氨基酸）的结构功能仍不清楚。在此，通过分析一组在大肠杆菌中表达的 ORF2 截短蛋白，我们发现高度保守的 C 末端半胱氨酸在截短的 ORF2 蛋白的寡聚化及其组装成 VLPs 中起着关键作用，通过形成二聚体-二聚体二硫键；并且用二硫苏糖醇（DTT）处理天然 HEV 颗粒诱导病毒衣壳的解体，表明二硫键对于稳定天然 HEV 衣壳是必需的。本研究阐明了 HEV 衣壳蛋白 C 末端区域的结构作用，有助于全面了解病毒衣壳组装过程。