6FYY

Structure of a partial yeast 48S preinitiation complex with eIF5 N-terminal domain (model C2)

This is a non-PDB format compatible entry.

Summary for 6FYY

• Entry DOI: 10.2210/pdb6fyy/pdb
• Related: 6FYX
• EMDB information: 4327 4328 4329 4330 4331
• Descriptor: tRNAi, 40S ribosomal protein S6, 40S ribosomal protein S7, ... (51 entities in total)
• Functional Keywords: ribosome, translation, initiation factors, 40s, eif1a, eif3, eif2, eif5, trnai, 48s pic, small ribosome subunit
• Biological source: Saccharomyces cerevisiae (Baker's yeast); More
• Total number of polymer chains: 47
• Total formula weight: 1762414.20

Authors

Llacer, J.L.,Hussain, T.,Gordiyenko, Y.,Ramakrishnan, V. (deposition date: 2018-03-12, release date: 2018-12-05, Last modification date: 2024-04-24)

Primary citation

Llacer, J.L.,Hussain, T.,Saini, A.K.,Nanda, J.D.,Kaur, S.,Gordiyenko, Y.,Kumar, R.,Hinnebusch, A.G.,Lorsch, J.R.,Ramakrishnan, V.
Translational initiation factor eIF5 replaces eIF1 on the 40S ribosomal subunit to promote start-codon recognition.
Elife, 7:-, 2018

PubMed Abstract: In eukaryotic translation initiation, AUG recognition of the mRNA requires accommodation of Met-tRNA in a 'P' state, which is antagonized by the factor eIF1. eIF5 is a GTPase activating protein (GAP) of eIF2 that additionally promotes stringent AUG selection, but the molecular basis of its dual function was unknown. We present a cryo-electron microscopy (cryo-EM) reconstruction of a yeast 48S pre-initiation complex (PIC), at an overall resolution of 3.0 Å, featuring the N-terminal domain (NTD) of eIF5 bound to the 40S subunit at the location vacated by eIF1. eIF5 interacts with and allows a more accommodated orientation of Met-tRNA. Substitutions of eIF5 residues involved in the eIF5-NTD/tRNA interaction influenced initiation at near-cognate UUG codons and the closed/open PIC conformation in vitro, consistent with direct stabilization of the codon:anticodon duplex by the wild-type eIF5-NTD. The present structure reveals the basis for a key role of eIF5 in start-codon selection.

PubMed: 30475211
DOI: 10.7554/eLife.39273

Experimental method

ELECTRON MICROSCOPY (3.02 Å)