6 research outputs found
Computational approach for calculating the probability of eukaryotic translation initiation from ribo-seq data that takes into account leaky scanning
Internal translation initiation and eIF4F/ATP-independent scanning of mRNA by eukaryotic ribosomal particles
Cross talk between energy cost and expression of Methyl Jasmonate-regulated genes: from DNA to protein
Cryo-EM study of start codon selection during archaeal translation initiation
Eukaryotic and archaeal translation initiation complexes have a common structural core comprising e/aIF1, e/aIF1A, the ternary complex (TC, e/aIF2-GTP-Met-tRNA(i)(Met)) and mRNA bound to the small ribosomal subunit. e/aIF2 plays a crucial role in this process but how this factor controls start codon selection remains unclear. Here, we present cryo-EM structures of the full archaeal 30S initiation complex showing two conformational states of the TC. In the first state, the TC is bound to the ribosome in a relaxed conformation with the tRNA oriented out of the P site. In the second state, the tRNA is accommodated within the peptidyl (P) site and the TC becomes constrained. This constraint is compensated by codon/anticodon base pairing, whereas in the absence of a start codon, aIF2 contributes to swing out the tRNA. This spring force concept highlights a mechanism of codon/anticodon probing by the initiator tRNA directly assisted by aIF2