4u1d

Structure of the PCI domain of translation initiation factor eIF3aStructure of the PCI domain of translation initiation factor eIF3a

Structural highlights

4u1d is a 3 chain structure with sequence from Saccharomyces cerevisiae S288C. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 3.3Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

EIF3A_YEAST Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is involved in protein synthesis and, together with other initiation factors, stimulates binding of mRNA and methionyl-tRNAi to the 40S ribosome.^[1] ^[2] ^[3] ^[4]

Publication Abstract from PubMed

Eukaryotic translation initiation requires the recruitment of the large, multiprotein eIF3 complex to the 40S ribosomal subunit. We present X-ray structures of all major components of the minimal, six-subunit Saccharomyces cerevisiae eIF3 core. These structures, together with electron microscopy reconstructions, cross-linking coupled to mass spectrometry, and integrative structure modeling, allowed us to position and orient all eIF3 components on the 40SeIF1 complex, revealing an extended, modular arrangement of eIF3 subunits. Yeast eIF3 engages 40S in a clamp-like manner, fully encircling 40S to position key initiation factors on opposite ends of the mRNA channel, providing a platform for the recruitment, assembly, and regulation of the translation initiation machinery. The structures of eIF3 components reported here also have implications for understanding the architecture of the mammalian 43S preinitiation complex and the complex of eIF3, 40S, and the hepatitis C internal ribosomal entry site RNA.

Molecular Architecture of the 40SeIF1eIF3 Translation Initiation Complex.,Erzberger JP, Stengel F, Pellarin R, Zhang S, Schaefer T, Aylett CH, Cimermancic P, Boehringer D, Sali A, Aebersold R, Ban N Cell. 2014 Aug 28;158(5):1123-35. doi: 10.1016/j.cell.2014.07.044. PMID:25171412^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Valasek L, Trachsel H, Hasek J, Ruis H. Rpg1, the Saccharomyces cerevisiae homologue of the largest subunit of mammalian translation initiation factor 3, is required for translational activity. J Biol Chem. 1998 Aug 14;273(33):21253-60. PMID:9694884
↑ Phan L, Schoenfeld LW, Valasek L, Nielsen KH, Hinnebusch AG. A subcomplex of three eIF3 subunits binds eIF1 and eIF5 and stimulates ribosome binding of mRNA and tRNA(i)Met. EMBO J. 2001 Jun 1;20(11):2954-65. PMID:11387228 doi:http://dx.doi.org/10.1093/emboj/20.11.2954
↑ Valasek L, Mathew AA, Shin BS, Nielsen KH, Szamecz B, Hinnebusch AG. The yeast eIF3 subunits TIF32/a, NIP1/c, and eIF5 make critical connections with the 40S ribosome in vivo. Genes Dev. 2003 Mar 15;17(6):786-99. PMID:12651896 doi:http://dx.doi.org/10.1101/gad.1065403
↑ Szamecz B, Rutkai E, Cuchalova L, Munzarova V, Herrmannova A, Nielsen KH, Burela L, Hinnebusch AG, Valasek L. eIF3a cooperates with sequences 5' of uORF1 to promote resumption of scanning by post-termination ribosomes for reinitiation on GCN4 mRNA. Genes Dev. 2008 Sep 1;22(17):2414-25. doi: 10.1101/gad.480508. PMID:18765792 doi:http://dx.doi.org/10.1101/gad.480508
↑ Erzberger JP, Stengel F, Pellarin R, Zhang S, Schaefer T, Aylett CH, Cimermancic P, Boehringer D, Sali A, Aebersold R, Ban N. Molecular Architecture of the 40SeIF1eIF3 Translation Initiation Complex. Cell. 2014 Aug 28;158(5):1123-35. doi: 10.1016/j.cell.2014.07.044. PMID:25171412 doi:http://dx.doi.org/10.1016/j.cell.2014.07.044

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OCA

[1] Valasek L, Trachsel H, Hasek J, Ruis H. Rpg1, the Saccharomyces cerevisiae homologue of the largest subunit of mammalian translation initiation factor 3, is required for translational activity. J Biol Chem. 1998 Aug 14;273(33):21253-60. PMID:9694884

[2] Phan L, Schoenfeld LW, Valasek L, Nielsen KH, Hinnebusch AG. A subcomplex of three eIF3 subunits binds eIF1 and eIF5 and stimulates ribosome binding of mRNA and tRNA(i)Met. EMBO J. 2001 Jun 1;20(11):2954-65. PMID:11387228 doi:http://dx.doi.org/10.1093/emboj/20.11.2954

[3] Valasek L, Mathew AA, Shin BS, Nielsen KH, Szamecz B, Hinnebusch AG. The yeast eIF3 subunits TIF32/a, NIP1/c, and eIF5 make critical connections with the 40S ribosome in vivo. Genes Dev. 2003 Mar 15;17(6):786-99. PMID:12651896 doi:http://dx.doi.org/10.1101/gad.1065403

[4] Szamecz B, Rutkai E, Cuchalova L, Munzarova V, Herrmannova A, Nielsen KH, Burela L, Hinnebusch AG, Valasek L. eIF3a cooperates with sequences 5' of uORF1 to promote resumption of scanning by post-termination ribosomes for reinitiation on GCN4 mRNA. Genes Dev. 2008 Sep 1;22(17):2414-25. doi: 10.1101/gad.480508. PMID:18765792 doi:http://dx.doi.org/10.1101/gad.480508

[5] Erzberger JP, Stengel F, Pellarin R, Zhang S, Schaefer T, Aylett CH, Cimermancic P, Boehringer D, Sali A, Aebersold R, Ban N. Molecular Architecture of the 40SeIF1eIF3 Translation Initiation Complex. Cell. 2014 Aug 28;158(5):1123-35. doi: 10.1016/j.cell.2014.07.044. PMID:25171412 doi:http://dx.doi.org/10.1016/j.cell.2014.07.044

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