The C-Terminal Fragment of the Ribosomal P Protein Complexed to Trichosanthin Reveals the Interaction between the Ribosome-Inactivating Protein and the Ribosome.
Primary Citation of Related Structures:   2JDL, 2JJR, 2VS6
PubMed Abstract: 
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 ...
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.
Organizational Affiliation: 
Department of Biochemistry, Centre for Protein Science and Crystallography and Molecular Biotechnology Programme, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China.