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Publication Abstract from PubMed

The antibiotic blasticidin S (BlaS) is a potent inhibitor of protein synthesis in bacteria and eukaryotes. We have determined a 3.4-A crystal structure of BlaS bound to a 70StRNA ribosome complex and performed biochemical and single-molecule FRET experiments to determine the mechanism of action of the antibiotic. We find that BlaS enhances tRNA binding to the P site of the large ribosomal subunit and slows down spontaneous intersubunit rotation in pretranslocation ribosomes. However, the antibiotic has negligible effect on elongation factor G catalyzed translocation of tRNA and mRNA. The crystal structure of the antibiotic-ribosome complex reveals that BlaS impedes protein synthesis through a unique mechanism by bending the 3' terminus of the P-site tRNA toward the A site of the large ribosomal subunit. Biochemical experiments demonstrate that stabilization of the deformed conformation of the P-site tRNA by BlaS strongly inhibits peptidyl-tRNA hydrolysis by release factors and, to a lesser extent, peptide bond formation.

Blasticidin S inhibits translation by trapping deformed tRNA on the ribosome.,Svidritskiy E, Ling C, Ermolenko DN, Korostelev AA Proc Natl Acad Sci U S A. 2013 Jul 23;110(30):12283-8. doi:, 10.1073/pnas.1304922110. Epub 2013 Jul 3. PMID:23824292^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.