5K0Y

m48S late-stage initiation complex, purified from rabbit reticulocytes lysates, displaying eIF2 ternary complex and eIF3 i and g subunits relocated to the intersubunit face

Summary for 5K0Y

• Entry DOI: 10.2210/pdb5k0y/pdb
• EMDB information: 8190
• Descriptor: tRNA, ribosomal protein uS13, Eukaryotic translation initiation factor 3 subunit G, ... (42 entities in total)
• Functional Keywords: eukaryotic translation initiation, ribosome, eif3 peripheral subunits, cryo-em, translation
• Biological source: Oryctolagus cuniculus (Rabbit); More
• Cellular location: Cytoplasm : O75821 O75821 Q5IH81 G1TN72
• Total number of polymer chains: 42
• Total formula weight: 1291316.63

Authors

Simonetti, A.,Brito Querido, J.,Myasnikov, A.G.,Mancera-Martinez, E.,Renaud, A.,Kuhn, L.,Hashem, Y. (deposition date: 2016-05-17, release date: 2016-07-13, Last modification date: 2018-04-18)

Primary citation

Simonetti, A.,Brito Querido, J.,Myasnikov, A.G.,Mancera-Martinez, E.,Renaud, A.,Kuhn, L.,Hashem, Y.
eIF3 Peripheral Subunits Rearrangement after mRNA Binding and Start-Codon Recognition.
Mol.Cell, 63:206-217, 2016

PubMed Abstract: mRNA translation initiation in eukaryotes requires the cooperation of a dozen eukaryotic initiation factors (eIFs) forming several complexes, which leads to mRNA attachment to the small ribosomal 40S subunit, mRNA scanning for start codon, and accommodation of initiator tRNA at the 40S P site. eIF3, composed of 13 subunits, 8 core (a, c, e, f, h, l, k, and m) and 5 peripheral (b, d, g, i, and j), plays a central role during this process. Here we report a cryo-electron microscopy structure of a mammalian 48S initiation complex at 5.8 Å resolution. It shows the relocation of subunits eIF3i and eIF3g to the 40S intersubunit face on the GTPase binding site, at a late stage in initiation. On the basis of a previous study, we demonstrate the relocation of eIF3b to the 40S intersubunit face, binding below the eIF2-Met-tRNAi(Met) ternary complex upon mRNA attachment. Our analysis reveals the deep rearrangement of eIF3 and unravels the molecular mechanism underlying eIF3 function in mRNA scanning and timing of ribosomal subunit joining.

PubMed: 27373335
DOI: 10.1016/j.molcel.2016.05.033

Experimental method

ELECTRON MICROSCOPY (5.8 Å)