Recognition of aminoacyl-tRNA: a common molecular mechanism revealed by cryo-EM |
| |
Authors: | Wen Li Xabier Agirrezabala Jianlin Lei Lamine Bouakaz Julie L Brunelle Rodrigo F Ortiz-Meoz Rachel Green Suparna Sanyal Mns Ehrenberg and Joachim Frank |
| |
Institution: | Wen Li, Xabier Agirrezabala, Jianlin Lei, Lamine Bouakaz, Julie L Brunelle, Rodrigo F Ortiz-Meoz, Rachel Green, Suparna Sanyal, Måns Ehrenberg, and Joachim Frank |
| |
Abstract: | The accuracy of ribosomal translation is achieved by an initial selection and a proofreading step, mediated by EF-Tu, which forms a ternary complex with aminoacyl(aa)-tRNA. To study the binding modes of different aa-tRNAs, we compared cryo-EM maps of the kirromycin-stalled ribosome bound with ternary complexes containing Phe-tRNAPhe, Trp-tRNATrp, or Leu-tRNALeuI. The three maps suggest a common binding manner of cognate aa-tRNAs in their specific binding with both the ribosome and EF-Tu. All three aa-tRNAs have the same ‘loaded spring' conformation with a kink and twist between the D-stem and anticodon stem. The three complexes are similarly integrated in an interaction network, extending from the anticodon loop through h44 and protein S12 to the EF-Tu-binding CCA end of aa-tRNA, proposed to signal cognate codon–anticodon interaction to the GTPase centre and tune the accuracy of aa-tRNA selection. |
| |
Keywords: | cryo‐EM decoding EF‐Tu ribosome |
|
|