8OZ0

Structure of a human 48S translation initiation complex with eIF4F and eIF4A

This is a non-PDB format compatible entry.

Summary for 8OZ0

• Entry DOI: 10.2210/pdb8oz0/pdb
• EMDB information: 17297
• Descriptor: Eukaryotic translation initiation factor 3 subunit E, Eukaryotic translation initiation factor 2 subunit 3, Eukaryotic translation initiation factor 3 subunit I, ... (58 entities in total)
• Functional Keywords: translation, eif4a, eif4f, initiation, ribosome, mrna
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 57
• Total formula weight: 2476483.59

Authors

Brito Querido, J.,Sokabe, M.,Diaz-Lopez, I.,Gordiyenko, Y.,Fraser, C.S.,Ramakrishnan, V. (deposition date: 2023-05-06, release date: 2024-02-07, Last modification date: 2024-04-24)

Primary citation

Brito Querido, J.,Sokabe, M.,Diaz-Lopez, I.,Gordiyenko, Y.,Fraser, C.S.,Ramakrishnan, V.
The structure of a human translation initiation complex reveals two independent roles for the helicase eIF4A.
Nat.Struct.Mol.Biol., 31:455-464, 2024

PubMed Abstract: Eukaryotic translation initiation involves recruitment of the 43S pre-initiation complex to the 5' end of mRNA by the cap-binding complex eIF4F, forming the 48S translation initiation complex (48S), which then scans along the mRNA until the start codon is recognized. We have previously shown that eIF4F binds near the mRNA exit channel of the 43S, leaving open the question of how mRNA secondary structure is removed as it enters the mRNA channel on the other side of the 40S subunit. Here we report the structure of a human 48S that shows that, in addition to the eIF4A that is part of eIF4F, there is a second eIF4A helicase bound at the mRNA entry site, which could unwind RNA secondary structures as they enter the 48S. The structure also reveals conserved interactions between eIF4F and the 43S, probaby explaining how eIF4F can promote mRNA recruitment in all eukaryotes.

PubMed: 38287194
DOI: 10.1038/s41594-023-01196-0

Experimental method

ELECTRON MICROSCOPY (3.5 Å)