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

Haohao Dong, Ping Li, Richard M Elliott, Changjiang Dong

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

Schmallenberg virus (SBV), a newly emerged orthobunyavirus (family Bunyaviridae), 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.
Original languageEnglish
Pages (from-to)5593-601
Number of pages9
JournalJournal of Virology
Volume87
Issue number10
DOIs
Publication statusPublished - May 2013

Keywords

  • Amino Acid Sequence
  • Crystallography, X-Ray
  • Models, Molecular
  • Molecular Sequence Data
  • Nucleoproteins
  • Orthobunyavirus
  • Protein Conformation
  • Protein Multimerization
  • RNA-Binding Proteins
  • Sequence Alignment
  • Virus Assembly
  • Virus Replication

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