What is the role of the cys-his motif in retroviral nucleocapsid (NC) proteins?

Bioessays. 1989 Dec;11(6):176-81. doi: 10.1002/bies.950110605.


Retroviruses encode a small, basic nucleocapsid (NC) protein that is found complexed to genomic RNA within the viral particle. The NC protein appears to function not only in a histone-like manner in packaging the RNA into the particle but also in specifically selecting the viral genomic RNA for packaging. A cysteine-histidine (cys-his) region, usually composed of 14 amino acids and reminiscent of the 'zinc fingers' of transcription factors, is the only highly conserved sequence element among the retroviral NC proteins. This review discusses the biochemical properties of NC, and its possible role(s) in retroviral replication. We also speculate on how the biochemical properties may relate to its function in RNA recognition and packaging.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Capsid / genetics*
  • Capsid / metabolism
  • Cysteine*
  • Histidine*
  • Molecular Sequence Data
  • Protein Conformation
  • Retroviridae / genetics*
  • Sequence Homology, Nucleic Acid
  • Viral Core Proteins / genetics*
  • Viral Core Proteins / metabolism


  • Viral Core Proteins
  • Histidine
  • Cysteine