Modular organization of SARS coronavirus nucleocapsid protein

J Biomed Sci. 2006 Jan;13(1):59-72. doi: 10.1007/s11373-005-9035-9. Epub 2005 Oct 14.


The SARS-CoV nucleocapsid (N) protein is a major antigen in severe acute respiratory syndrome. It binds to the viral RNA genome and forms the ribonucleoprotein core. The SARS-CoV N protein has also been suggested to be involved in other important functions in the viral life cycle. Here we show that the N protein consists of two non-interacting structural domains, the N-terminal RNA-binding domain (RBD) (residues 45-181) and the C-terminal dimerization domain (residues 248-365) (DD), surrounded by flexible linkers. The C-terminal domain exists exclusively as a dimer in solution. The flexible linkers are intrinsically disordered and represent potential interaction sites with other protein and protein-RNA partners. Bioinformatics reveal that other coronavirus N proteins could share the same modular organization. This study provides information on the domain structure partition of SARS-CoV N protein and insights into the differing roles of structured and disordered regions in coronavirus nucleocapsid proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, Viral / chemistry*
  • Antigens, Viral / genetics
  • Coronavirus Nucleocapsid Proteins
  • Humans
  • Molecular Sequence Data
  • Nucleocapsid Proteins / chemistry*
  • Nucleocapsid Proteins / genetics
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Protein Structure, Secondary*
  • Protein Structure, Tertiary
  • Sequence Alignment
  • Sequence Homology, Amino Acid


  • Antigens, Viral
  • Coronavirus Nucleocapsid Proteins
  • Nucleocapsid Proteins
  • Peptide Fragments