4K51

Crystal Structure of the PCI domain of eIF3a

Summary for 4K51

• Entry DOI: 10.2210/pdb4k51/pdb
• Descriptor: Eukaryotic translation initiation factor 3 subunit A (1 entity in total)
• Functional Keywords: eif3, pci domain, translation initiation, biosynthetic protein
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Cellular location: Cytoplasm (By similarity): P38249
• Total number of polymer chains: 2
• Total formula weight: 51228.23

Authors

Khoshnevis, S.,Neumann, P.,Ficner, R. (deposition date: 2013-04-12, release date: 2014-01-15, Last modification date: 2024-02-28)

Primary citation

Khoshnevis, S.,Gunisova, S.,Vlckova, V.,Kouba, T.,Neumann, P.,Beznoskova, P.,Ficner, R.,Valasek, L.S.
Structural integrity of the PCI domain of eIF3a/TIF32 is required for mRNA recruitment to the 43S pre-initiation complexes.
Nucleic Acids Res., 42:4123-4139, 2014

PubMed Abstract: Transfer of genetic information from genes into proteins is mediated by messenger RNA (mRNA) that must be first recruited to ribosomal pre-initiation complexes (PICs) by a mechanism that is still poorly understood. Recent studies showed that besides eIF4F and poly(A)-binding protein, eIF3 also plays a critical role in this process, yet the molecular mechanism of its action is unknown. We showed previously that the PCI domain of the eIF3c/NIP1 subunit of yeast eIF3 is involved in RNA binding. To assess the role of the second PCI domain of eIF3 present in eIF3a/TIF32, we performed its mutational analysis and identified a 10-Ala-substitution (Box37) that severely reduces amounts of model mRNA in the 43-48S PICs in vivo as the major, if not the only, detectable defect. Crystal structure analysis of the a/TIF32-PCI domain at 2.65-Å resolution showed that it is required for integrity of the eIF3 core and, similarly to the c/NIP1-PCI, is capable of RNA binding. The putative RNA-binding surface defined by positively charged areas contains two Box37 residues, R363 and K364. Their substitutions with alanines severely impair the mRNA recruitment step in vivo suggesting that a/TIF32-PCI represents one of the key domains ensuring stable and efficient mRNA delivery to the PICs.

PubMed: 24423867
DOI: 10.1093/nar/gkt1369

Experimental method

X-RAY DIFFRACTION (2.65 Å)