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| ==Structure of mammalian eIF3 in the context of the 43S preinitiation complex== | | ==Structure of mammalian eIF3 in the context of the 43S preinitiation complex== |
| <StructureSection load='5a5t' size='340' side='right' caption='[[5a5t]], [[Resolution|resolution]] 6.00Å' scene=''> | | <SX load='5a5t' size='340' side='right' viewer='molstar' caption='[[5a5t]], [[Resolution|resolution]] 6.00Å' scene=''> |
| == Structural highlights == | | == Structural highlights == |
| <table><tr><td colspan='2'>[[5a5t]] is a 8 chain structure with sequence from [http://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5A5T OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5A5T FirstGlance]. <br> | | <table><tr><td colspan='2'>[[5a5t]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5A5T OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5A5T FirstGlance]. <br> |
| </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5a5u|5a5u]]</td></tr> | | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 6Å</td></tr> |
| <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Ubiquitinyl_hydrolase_1 Ubiquitinyl hydrolase 1], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.19.12 3.4.19.12] </span></td></tr>
| | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5a5t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5a5t OCA], [https://pdbe.org/5a5t PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5a5t RCSB], [https://www.ebi.ac.uk/pdbsum/5a5t PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5a5t ProSAT]</span></td></tr> |
| <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5a5t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5a5t OCA], [http://www.rcsb.org/pdb/explore.do?structureId=5a5t RCSB], [http://www.ebi.ac.uk/pdbsum/5a5t PDBsum]</span></td></tr> | |
| </table> | | </table> |
| == Function == | | == Function == |
| [[http://www.uniprot.org/uniprot/G1T3L2_RABIT G1T3L2_RABIT]] Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis. The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S preinitiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation.[HAMAP-Rule:MF_03010] [[http://www.uniprot.org/uniprot/G1SUC8_RABIT G1SUC8_RABIT]] Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis. The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S preinitiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation. Required for nonsense-mediated mRNA decay (NMD); may act in conjunction with UPF2 to divert mRNAs from translation to the NMD pathway. May interact with MCM7 and EPAS1 and regulate the proteasome-mediated degradation of these proteins.[HAMAP-Rule:MF_03004] [[http://www.uniprot.org/uniprot/G1U971_RABIT G1U971_RABIT]] Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis. The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S preinitiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation.[HAMAP-Rule:MF_03002] [[http://www.uniprot.org/uniprot/G1SLW8_RABIT G1SLW8_RABIT]] Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis. The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S preinitiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation.[HAMAP-Rule:MF_03012] [[http://www.uniprot.org/uniprot/G1SMZ5_RABIT G1SMZ5_RABIT]] Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis. The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S preinitiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation.[HAMAP-Rule:MF_03000] [[http://www.uniprot.org/uniprot/U3KNL5_RABIT U3KNL5_RABIT]] Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis. The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S preinitiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation.[HAMAP-Rule:MF_03005] [[http://www.uniprot.org/uniprot/G1ST95_RABIT G1ST95_RABIT]] Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis. The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S preinitiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation.[HAMAP-Rule:MF_03007] | | [https://www.uniprot.org/uniprot/G1U971_RABIT G1U971_RABIT] Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis. The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S preinitiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation.[HAMAP-Rule:MF_03002] |
| | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == |
| | 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. |
| | |
| | Structure of mammalian eIF3 in the context of the 43S preinitiation complex.,des Georges A, Dhote V, Kuhn L, Hellen CU, Pestova TV, Frank J, Hashem Y Nature. 2015 Sep 24;525(7570):491-5. doi: 10.1038/nature14891. Epub 2015 Sep 7. PMID:26344199<ref>PMID:26344199</ref> |
| | |
| | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| | </div> |
| | <div class="pdbe-citations 5a5t" style="background-color:#fffaf0;"></div> |
| | |
| | ==See Also== |
| | *[[Eukaryotic initiation factor 3D structures|Eukaryotic initiation factor 3D structures]] |
| | == References == |
| | <references/> |
| __TOC__ | | __TOC__ |
| </StructureSection> | | </SX> |
| | [[Category: Large Structures]] |
| [[Category: Oryctolagus cuniculus]] | | [[Category: Oryctolagus cuniculus]] |
| [[Category: Ubiquitinyl hydrolase 1]]
| | [[Category: Dhote V]] |
| [[Category: Dhote, V]] | | [[Category: Frank J]] |
| [[Category: Frank, J]] | | [[Category: Hashem Y]] |
| [[Category: Hashem, Y]] | | [[Category: Hellen CUT]] |
| [[Category: Hellen, C U.T]] | | [[Category: Kuhn L]] |
| [[Category: Kuhn, L]] | | [[Category: Pestova TV]] |
| [[Category: Pestova, T V]] | | [[Category: Des-Georges A]] |
| [[Category: Des-Georges, A]] | |
| [[Category: Eif3]]
| |
| [[Category: Eif3d]]
| |
| [[Category: Eif3g/i/b]]
| |
| [[Category: Eukaryotic initiation factor 3]]
| |
| [[Category: Hydrolase]]
| |
| [[Category: Pci/mpn core]]
| |
| [[Category: Preinitiation complex]]
| |