Publication Date:
2015-09-08
Description:
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 approximately 6 A 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.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4719162/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4719162/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉des Georges, Amedee -- Dhote, Vidya -- Kuhn, Lauriane -- Hellen, Christopher U T -- Pestova, Tatyana V -- Frank, Joachim -- Hashem, Yaser -- R01 GM029169/GM/NIGMS NIH HHS/ -- R01 GM059660/GM/NIGMS NIH HHS/ -- R01 GM29169/GM/NIGMS NIH HHS/ -- R01 GM59660/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Sep 24;525(7570):491-5. doi: 10.1038/nature14891. Epub 2015 Sep 7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉HHMI, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA. ; Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York 11203, USA. ; CNRS, Proteomic Platform Strasbourg - Esplanade, Strasbourg 67084, France. ; Department of Biological Sciences, Columbia University, New York, New York 10032, USA. ; CNRS, Architecture et Reactivite de l'ARN, Universite de Strasbourg, Strasbourg 67084, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26344199" target="_blank"〉PubMed〈/a〉
Keywords:
Binding Sites
;
Codon, Initiator/genetics
;
Cryoelectron Microscopy
;
Eukaryotic Initiation Factor-2/chemistry/metabolism
;
Eukaryotic Initiation Factor-3/*chemistry/*metabolism
;
Humans
;
Models, Molecular
;
Multiprotein Complexes/*chemistry/*metabolism
;
*Peptide Chain Initiation, Translational
;
Peptide Initiation Factors/metabolism
;
Protein Structure, Secondary
;
Protein Subunits/chemistry/metabolism
;
RNA Helicases/chemistry/metabolism
;
RNA, Messenger/genetics/metabolism
;
RNA, Transfer, Met/metabolism
;
Ribosome Subunits, Small, Eukaryotic/chemistry/metabolism
;
Ribosomes/*chemistry/*metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
