The C-terminal fragment of the ribosomal P protein complexed to trichosanthin reveals the interaction between the ribosome-inactivating protein and the ribosome

Nucleic Acids Res. 2009 Feb;37(2):602-10. doi: 10.1093/nar/gkn922. Epub 2008 Dec 10.


Ribosome-inactivating proteins (RIPs) inhibit protein synthesis by enzymatically depurinating a specific adenine residue at the sarcin-ricin loop of the 28S rRNA, which thereby prevents the binding of elongation factors to the GTPase activation centre of the ribosome. Here, we present the 2.2 A crystal structure of trichosanthin (TCS) complexed to the peptide SDDDMGFGLFD, which corresponds to the conserved C-terminal elongation factor binding domain of the ribosomal P protein. The N-terminal region of this peptide interacts with Lys173, Arg174 and Lys177 in TCS, while the C-terminal region is inserted into a hydrophobic pocket. The interaction with the P protein contributes to the ribosome-inactivating activity of TCS. This 11-mer C-terminal P peptide can be docked with selected important plant and bacterial RIPs, indicating that a similar interaction may also occur with other RIPs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Models, Molecular
  • Molecular Sequence Data
  • Peptides / chemistry
  • Phosphoproteins / chemistry*
  • Protein Structure, Tertiary
  • Ribosomal Proteins / chemistry*
  • Sequence Homology, Amino Acid
  • Trichosanthin / chemistry*


  • Peptides
  • Phosphoproteins
  • Ribosomal Proteins
  • phosphoprotein P2, ribosomal
  • ribosomal phosphoprotein P1
  • ribosomal protein P0
  • Trichosanthin

Associated data

  • PDB/2JDL
  • PDB/2JJR
  • PDB/2VS6