Viral IRES RNA structures and ribosome interactions

Trends Biochem Sci. 2008 Jun;33(6):274-83. doi: 10.1016/j.tibs.2008.04.007. Epub 2008 May 28.


In eukaryotes, protein synthesis initiates primarily by a mechanism that requires a modified nucleotide 'cap' on the mRNA and also proteins that recruit and position the ribosome. Many pathogenic viruses use an alternative, cap-independent mechanism that substitutes RNA structure for the cap and many proteins. The RNAs driving this process are called internal ribosome-entry sites (IRESs) and some are able to bind the ribosome directly using a specific 3D RNA structure. Recent structures of IRES RNAs and IRES-ribosome complexes are revealing the structural basis of viral IRES' 'hijacking' of the protein-making machinery. It now seems that there are fundamental differences in the 3D structures used by different IRESs, although there are some common features in how they interact with ribosomes.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Nucleic Acid Conformation
  • RNA Caps / chemistry
  • RNA Caps / metabolism*
  • RNA, Viral / chemistry
  • RNA, Viral / metabolism*
  • Ribosomes / chemistry
  • Ribosomes / metabolism*
  • Viruses / metabolism*


  • RNA Caps
  • RNA, Viral