The central role of protein S12 in organizing the structure of the decoding site of the ribosome |
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| Authors: | Hasan Demirci Leyi Wang Frank V. Murphy IV Eileen L. Murphy Jennifer F. Carr Scott C. Blanchard Gerwald Jogl Albert E. Dahlberg Steven T. Gregory |
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| Affiliation: | 1.Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, USA;2.Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York 10021, USA;3.NE-CAT/Cornell University, Argonne, Illinois 60439, USA |
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| Abstract: | ![]()
The ribosome decodes mRNA by monitoring the geometry of codon–anticodon base-pairing using a set of universally conserved 16S rRNA nucleotides within the conformationally dynamic decoding site. By applying single-molecule FRET and X-ray crystallography, we have determined that conditional-lethal, streptomycin-dependence mutations in ribosomal protein S12 interfere with tRNA selection by allowing conformational distortions of the decoding site that impair GTPase activation of EF-Tu during the tRNA selection process. Distortions in the decoding site are reversed by streptomycin or by a second-site suppressor mutation in 16S rRNA. These observations encourage a refinement of the current model for decoding, wherein ribosomal protein S12 and the decoding site collaborate to optimize codon recognition and substrate discrimination during the early stages of the tRNA selection process. |
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| Keywords: | ribosome rRNA decoding single-molecule FRET X-ray crystallography |
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