A structural view of translation initiation in bacteria.

Angelita Simonetti (1) , Stefano Marzi (1, 2) , L. Jenner (1) , Alexander Myasnikov (1) , Pascale Romby (2) , Gulnara Yusupova (1) , Bruno Klaholz (1) , Marat Yusupov (1, 2)

1 IGBMC - Institut de génétique et biologie moléculaire et cellulaire
2 ARN - Architecture et réactivité de l'ARN

The assembly of the protein synthesis machinery occurs during translation initiation. In bacteria, this process involves the binding of messenger RNA(mRNA) start site and fMet-tRNA(fMet) to the ribosome, which results in the formation of the first codon-anticodon interaction and sets the reading frame for the decoding of the mRNA. This interaction takes place in the peptidyl site of the 30S ribosomal subunit and is controlled by the initiation factors IF1, IF2 and IF3 to form the 30S initiation complex. The binding of the 50S subunit and the ejection of the IFs mark the irreversible transition to the elongation phase. Visualization of these ligands on the ribosome has been achieved by cryo-electron microscopy and X-ray crystallography studies, which has helped to understand the mechanism of translation initiation at the molecular level. Conformational changes associated with different functional states provide a dynamic view of the initiation process and of its regulation.

Mots clés: Initiation of translation; regulation of translation; ribosome structure; mRNA; initiation factor; initiator tRNA; functional ribosomal complexes

Domaines: Biochimie, Biologie Moléculaire; Biologie cellulaire

Angelita Simonetti, Stefano Marzi, L. Jenner, Alexander Myasnikov, Pascale Romby, et al.. A structural view of translation initiation in bacteria.. Cellular and Molecular Life Sciences, 2009, 66 (3), pp.423-36. ⟨10.1007/s00018-008-8416-4⟩. ⟨hal-00391779⟩