Structural basis and functional analysis of the SARS coronavirus nsp14–nsp10 complex

Nonstructural protein 14 (nsp14) of coronaviruses (CoV) is important for viral replication and transcription. The N-terminal exoribonuclease (ExoN) domain plays a proofreading role for prevention of lethal mutagenesis, and the C-terminal domain functions as a (guanine-N7) methyl transferase (N7-MTase) for mRNA capping. The molecular basis of both these functions is unknown. Here, we describe crystal structures of severe acute respiratory syndrome (SARS)-CoV nsp14 in complex with its activator nonstructural protein10 (nsp10) and functional ligands. One molecule of nsp10 interacts with ExoN of nsp14 to stabilize it and stimulate its activity. Although the catalytic core of nsp14 ExoN is reminiscent of…

• NN
  National Natural Science Foundation of China

  Awards: 81330036, 2014CBA02003
• CA
  Chinese Academy of Sciences

  Award: XDB08020200
• MO
  Ministry of Science and Technology of the People's Republic of China

  Award: 2014CB542800