Crystal structure of Schmallenberg orthobunyavirus nucleoprotein-RNA complex reveals a novel RNA sequestration mechanism

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

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Schmallenberg virus (SBV) is a newly emerged orthobunyavirus (family Bunyaviridae) that has caused severe disease in the offspring of farm animals across Europe. Like all orthobunyaviruses, SBV contains a tripartite negative-sense RNA genome that is encapsidated by the viral nucleocapsid (N) protein in the form of a ribonucleoprotein complex (RNP). We recently reported the three-dimensional structure of SBV N that revealed a novel fold. Here we report the crystal structure of the SBV N protein in complex with a 42-nt-long RNA to 2.16 Å resolution. The complex comprises a tetramer of N that encapsidates the RNA as a cross-shape inside the protein ring structure, with each protomer bound to 11 ribonucleotides. Eight bases are bound in the positively charged cleft between the N- and C-terminal domains of N, and three bases are shielded by the extended N-terminal arm. SBV N appears to sequester RNA using a different mechanism compared with the nucleoproteins of other negative-sense RNA viruses. Furthermore, the structure suggests that RNA binding results in conformational changes of some residues in the RNA-binding cleft and the N- and C-terminal arms. Our results provide new insights into the novel mechanism of RNA encapsidation by orthobunyaviruses.
Original languageEnglish
Pages (from-to)1129-36
Number of pages8
JournalRNA
Volume19
Issue number8
DOIs
Publication statusPublished - Aug 2013

Keywords

  • Animals
  • Binding Sites
  • Crystallography, X-Ray
  • Macromolecular Substances
  • Microscopy, Electron
  • Models, Molecular
  • Nucleic Acid Conformation
  • Nucleocapsid Proteins
  • Orthobunyavirus
  • Protein Structure, Quaternary
  • RNA, Viral
  • Static Electricity

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