Identification of specific Rp-phosphate oxygens in the tRNA anticodon loop required for ribosomal P-site binding.

Abstract

tRNA binding to the ribosomal P site is dependent not only on correct codon-anticodon interaction but also involves identification of structural elements of tRNA by the ribosome. By using a phosphorothioate substitution-interference approach, we identified specific nonbridging Rp-phosphate oxygens in the anticodon loop of tRNA(Phe) from Escherichia coli which are required for P-site binding. Stereospecific involvement of phosphate oxygens at these positions was confirmed by using synthetic anticodon arm analogues at which single Rp- or Sp-phosphorothioates were incorporated. Identical interference results with yeast tRNA(Phe) and E. coli tRNA(fMet) indicate a common backbone conformation or common recognition elements in the anticodon loop of tRNAs. N-ethyl-N-nitrosourea modification-interference experiments with natural tRNAs point to the importance of the same phosphates in the loop. Guided by the crystal structure of tRNA(Phe), we propose that specific Rp-phosphate oxygens are required for anticodon loop ("U-turn") stabilization or are involved in interactions with the ribosome on correct tRNA-mRNA complex formation.

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Cite this paper

@article{Schnitzer1997IdentificationOS, title={Identification of specific Rp-phosphate oxygens in the tRNA anticodon loop required for ribosomal P-site binding.}, author={W Schnitzer and Uwe von Ahsen}, journal={Proceedings of the National Academy of Sciences of the United States of America}, year={1997}, volume={94 24}, pages={12823-8} }