3ZWL

Structure of eukaryotic translation initiation factor eIF3i complex with eIF3b C-terminus (655-700)

Summary for 3ZWL

• Entry DOI: 10.2210/pdb3zwl/pdb
• Descriptor: EUKARYOTIC TRANSLATION INITIATION FACTOR 3 SUBUNIT I, EUKARYOTIC TRANSLATION INITIATION FACTOR 3 SUBUNIT B (3 entities in total)
• Functional Keywords: translation
• Biological source: SACCHAROMYCES CEREVISIAE (BAKER'S YEAST); More
• Cellular location: Cytoplasm (Probable): P40217 P06103
• Total number of polymer chains: 4
• Total formula weight: 94731.65

Authors

Daujotyte, D.,Lukavsky, P.J. (deposition date: 2011-08-01, release date: 2011-10-05, Last modification date: 2024-05-08)

Primary citation

Herrmannova, A.,Daujotyte, D.,Yang, J.C.,Cuchalova, L.,Gorrec, F.,Wagner, S.,Danyi, I.,Lukavsky, P.J.,Shivaya Valasek, L.
Structural Analysis of an Eif3 Subcomplex Reveals Conserved Interactions Required for a Stable and Proper Translation Pre-Initiation Complex Assembly.
Nucleic Acids Res., 40:2294-, 2012

PubMed Abstract: Translation initiation factor eIF3 acts as the key orchestrator of the canonical initiation pathway in eukaryotes, yet its structure is greatly unexplored. We report the 2.2 Å resolution crystal structure of the complex between the yeast seven-bladed β-propeller eIF3i/TIF34 and a C-terminal α-helix of eIF3b/PRT1, which reveals universally conserved interactions. Mutating these interactions displays severe growth defects and eliminates association of eIF3i/TIF34 and strikingly also eIF3g/TIF35 with eIF3 and 40S subunits in vivo. Unexpectedly, 40S-association of the remaining eIF3 subcomplex and eIF5 is likewise destabilized resulting in formation of aberrant pre-initiation complexes (PICs) containing eIF2 and eIF1, which critically compromises scanning arrest on mRNA at its AUG start codon suggesting that the contacts between mRNA and ribosomal decoding site are impaired. Remarkably, overexpression of eIF3g/TIF35 suppresses the leaky scanning and growth defects most probably by preventing these aberrant PICs to form. Leaky scanning is also partially suppressed by eIF1, one of the key regulators of AUG recognition, and its mutant sui1(G107R) but the mechanism differs. We conclude that the C-terminus of eIF3b/PRT1 orchestrates co-operative recruitment of eIF3i/TIF34 and eIF3g/TIF35 to the 40S subunit for a stable and proper assembly of 48S pre-initiation complexes necessary for stringent AUG recognition on mRNAs.

PubMed: 22090426
DOI: 10.1093/NAR/GKR765

Experimental method

X-RAY DIFFRACTION (2.2 Å)