Recognition of aminoacyl-tRNA: a common molecular mechanism revealed by cryo-EM.
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-tRNA(Phe), Trp-tRNA(Trp), or Leu-tRNA(LeuI). 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.
Li
Wen
W
Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
Agirrezabala
Xabier
X
Lei
Jianlin
J
Bouakaz
Lamine
L
Brunelle
Julie L
JL
Ortiz-Meoz
Rodrigo F
RF
Green
Rachel
R
Sanyal
Suparna
S
Ehrenberg
Måns
M
Frank
Joachim
J
D020285:Cryoelectron Microscopy; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D010444:Peptide Elongation Factor Tu / Q000737:chemistry* / Q000378:metabolism*; D020836:Protein Structure, Quaternary; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011728:Pyridones / Q000494:pharmacology; D012343:RNA, Transfer / Q000737:chemistry* / Q000378:metabolism*; D012270:Ribosomes / Q000737:chemistry* / Q000378:metabolism*
D011500:Protein Synthesis Inhibitors; D011728:Pyridones; D012343:RNA, Transfer; D010444:Peptide Elongation Factor Tu; C008536:mocimycin