X-ray crystallographic structure of the Norwalk virus capsid

Science. 1999 Oct 8;286(5438):287-90. doi: 10.1126/science.286.5438.287.


Norwalk virus, a noncultivatable human calicivirus, is the major cause of epidemic gastroenteritis in humans. The first x-ray structure of a calicivirus capsid, which consists of 180 copies of a single protein, has been determined by phase extension from a low-resolution electron microscopy structure. The capsid protein has a protruding (P) domain connected by a flexible hinge to a shell (S) domain that has a classical eight-stranded beta-sandwich motif. The structure of the P domain is unlike that of any other viral protein with a subdomain exhibiting a fold similar to that of the second domain in the eukaryotic translation elongation factor-Tu. This subdomain, located at the exterior of the capsid, has the largest sequence variation among Norwalk-like human caliciviruses and is likely to contain the determinants of strain specificity and cell binding.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Capsid / chemistry*
  • Capsid / metabolism
  • Capsid Proteins*
  • Cryoelectron Microscopy
  • Crystallography, X-Ray
  • Dimerization
  • Genome, Viral
  • Humans
  • Hydrogen Bonding
  • Image Processing, Computer-Assisted
  • Models, Molecular
  • Molecular Sequence Data
  • Norwalk virus / chemistry*
  • Norwalk virus / genetics
  • Norwalk virus / physiology
  • Protein Conformation
  • Protein Folding
  • Protein Structure, Secondary
  • Recombinant Proteins / chemistry
  • Virus Assembly


  • Capsid Proteins
  • Norwalk virus capsid
  • Recombinant Proteins