5A5U

Structure of mammalian eIF3 in the context of the 43S preinitiation complex

Summary for 5A5U

• Entry DOI: 10.2210/pdb5a5u/pdb
• Related: 5A5T
• EMDB information: 3057
• Descriptor: EUKARYOTIC INITIATION FACTOR 3, EUKARYOTIC TRANSLATION INITIATION FACTOR 3 SUBUNIT B, EUKARYOTIC TRANSLATION INITIATION FACTOR 3 SUBUNIT I (3 entities in total)
• Functional Keywords: translation, eif3, eif3 octamer core, mammalian preinitiation 34s complex, eif3g/i/b, eif3d
• Biological source: ORYCTOLAGUS CUNICULUS (RABBIT); More
• Total number of polymer chains: 3
• Total formula weight: 167819.39

Authors

des-Georges, A.,Dhote, V.,Kuhn, L.,Hellen, C.U.T.,Pestova, T.V.,Frank, J.,Hashem, Y. (deposition date: 2015-06-21, release date: 2015-09-09, Last modification date: 2024-05-08)

Primary citation

Des-Georges, A.,Dhote, V.,Kuhn, L.,Hellen, C.U.T.,Pestova, T.V.,Frank, J.,Hashem, Y.
Structure of Mammalian Eif3 in the Context of the 43S Preinitiation Complex.
Nature, 525:491-, 2015

PubMed Abstract: During eukaryotic translation initiation, 43S complexes, comprising a 40S ribosomal subunit, initiator transfer RNA and initiation factors (eIF) 2, 3, 1 and 1A, attach to the 5'-terminal region of messenger RNA and scan along it to the initiation codon. Scanning on structured mRNAs also requires the DExH-box protein DHX29. Mammalian eIF3 contains 13 subunits and participates in nearly all steps of translation initiation. Eight subunits having PCI (proteasome, COP9 signalosome, eIF3) or MPN (Mpr1, Pad1, amino-terminal) domains constitute the structural core of eIF3, to which five peripheral subunits are flexibly linked. Here we present a cryo-electron microscopy structure of eIF3 in the context of the DHX29-bound 43S complex, showing the PCI/MPN core at ∼6 Å resolution. It reveals the organization of the individual subunits and their interactions with components of the 43S complex. We were able to build near-complete polyalanine-level models of the eIF3 PCI/MPN core and of two peripheral subunits. The implications for understanding mRNA ribosomal attachment and scanning are discussed.

PubMed: 26344199
DOI: 10.1038/NATURE14891

Experimental method

ELECTRON MICROSCOPY (9 Å)