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.

Subject headings

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Keyword

cryo-EM

decoding

EF-Tu

ribosome

Biology

Biologi

Molecular Biology

Molekylärbiologi

Publication and Content Type

ref (subject category)

art (subject category)