Structure of schmallenberg orthobunyavirus nucleoprotein suggests a novel mechanism of genome encapsidation

Dong, H., Li, P., Elliott, R.M. and Dong, C. (2013) Structure of schmallenberg orthobunyavirus nucleoprotein suggests a novel mechanism of genome encapsidation. Journal of Virology, 87(10), pp. 5593-5601. (doi: 10.1128/JVI.00223-13)

Abstract

Schmallenberg virus (SBV), a newly emerged orthobunyavirus (family <i>Bunyaviridae</i>), has spread rapidly across Europe and has caused congenital abnormalities in the offspring of cattle, sheep, and goats. Like other orthobunyaviruses, SBV contains a tripartite negative-sense RNA genome that encodes four structural and two nonstructural proteins. The nucleoprotein (N) encapsidates the three viral genomic RNA segments and plays a crucial role in viral RNA transcription and replication. Here we report the crystal structure of the bacterially expressed SBV nucleoprotein to a 3.06-Å resolution. The protomer is composed of two domains (N-terminal and C-terminal domains) with flexible N-terminal and C-terminal arms. The N protein has a novel fold and forms a central positively charged cleft for genomic RNA binding. The nucleoprotein purified under native conditions forms a tetramer, while the nucleoprotein obtained following denaturation and refolding forms a hexamer. Our structural and functional analyses demonstrate that both N-terminal and C-terminal arms are involved in N-N interaction and oligomerization and play an essential role in viral RNA synthesis, suggesting a novel mechanism for viral RNA encapsidation and transcription.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Elliott, Professor Richard
• Authors: Dong, H., Li, P., Elliott, R.M., and Dong, C.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: Journal of Virology
• ISSN: 0022-538X
• ISSN (Online): 1098-5514