View source for 8b6z


==CryoEM Structure of Extended eEF1A bound to the Ribosome in the Classical Pre State==
<StructureSection load='8b6z' size='340' side='right'caption='[[8b6z]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8b6z]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8B6Z OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8B6Z FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.9&#8491;</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=8b6z FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8b6z OCA], [https://pdbe.org/8b6z PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8b6z RCSB], [https://www.ebi.ac.uk/pdbsum/8b6z PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8b6z ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/EF1A2_HUMAN EF1A2_HUMAN] This protein promotes the GTP-dependent binding of aminoacyl-tRNA to the A-site of ribosomes during protein biosynthesis.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The dynamic ribosome-translocon complex, which resides at the endoplasmic reticulum (ER) membrane, produces a major fraction of the human proteome(1,2). It governs the synthesis, translocation, membrane insertion, N-glycosylation, folding and disulfide-bond formation of nascent proteins. Although individual components of this machinery have been studied at high resolution in isolation(3-7), insights into their interplay in the native membrane remain limited. Here we use cryo-electron tomography, extensive classification and molecular modelling to capture snapshots of mRNA translation and protein maturation at the ER membrane at molecular resolution. We identify a highly abundant classical pre-translocation intermediate with eukaryotic elongation factor 1a (eEF1a) in an extended conformation, suggesting that eEF1a may remain associated with the ribosome after GTP hydrolysis during proofreading. At the ER membrane, distinct polysomes bind to different ER translocons specialized in the synthesis of proteins with signal peptides or multipass transmembrane proteins with the translocon-associated protein complex (TRAP) present in both. The near-complete atomic model of the most abundant ER translocon variant comprising the protein-conducting channel SEC61, TRAP and the oligosaccharyltransferase complex A (OSTA) reveals specific interactions of TRAP with other translocon components. We observe stoichiometric and sub-stoichiometric cofactors associated with OSTA, which are likely to include protein isomerases. In sum, we visualize ER-bound polysomes with their coordinated downstream machinery.

Visualization of translation and protein biogenesis at the ER membrane.,Gemmer M, Chaillet ML, van Loenhout J, Cuevas Arenas R, Vismpas D, Grollers-Mulderij M, Koh FA, Albanese P, Scheltema RA, Howes SC, Kotecha A, Fedry J, Forster F Nature. 2023 Feb;614(7946):160-167. doi: 10.1038/s41586-022-05638-5. Epub 2023 , Jan 25. PMID:36697828<ref>PMID:36697828</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8b6z" style="background-color:#fffaf0;"></div>

==See Also==
*[[Elongation factor 3D structures|Elongation factor 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Fedry JMM]]
[[Category: Forster FG]]
[[Category: Gemmer M]]