8e1m: Difference between revisions
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==Cryo-EM structure of the endogenous core TIM23 complex from S. cerevisiae== | |||
<StructureSection load='8e1m' size='340' side='right'caption='[[8e1m]], [[Resolution|resolution]] 2.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[8e1m]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus] and [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8E1M OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8E1M 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]] 2.9Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CDL:CARDIOLIPIN'>CDL</scene>, <scene name='pdbligand=PTY:PHOSPHATIDYLETHANOLAMINE'>PTY</scene></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=8e1m FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8e1m OCA], [https://pdbe.org/8e1m PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8e1m RCSB], [https://www.ebi.ac.uk/pdbsum/8e1m PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8e1m ProSAT]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Mitochondria import nearly all of their approximately 1,000-2,000 constituent proteins from the cytosol across their double-membrane envelope(1-5). Genetic and biochemical studies have shown that the conserved protein translocase, termed the TIM23 complex, mediates import of presequence-containing proteins (preproteins) into the mitochondrial matrix and inner membrane. Among about ten different subunits of the TIM23 complex, the essential multipass membrane protein Tim23, together with the evolutionarily related protein Tim17, has long been postulated to form a protein-conducting channel(6-11). However, the mechanism by which these subunits form a translocation path in the membrane and enable the import process remains unclear due to a lack of structural information. Here we determined the cryo-electron microscopy structure of the core TIM23 complex (heterotrimeric Tim17-Tim23-Tim44) from Saccharomyces cerevisiae. Contrary to the prevailing model, Tim23 and Tim17 themselves do not form a water-filled channel, but instead have separate, lipid-exposed concave cavities that face in opposite directions. Our structural and biochemical analyses show that the cavity of Tim17, but not Tim23, forms the protein translocation path, whereas Tim23 probably has a structural role. The results further suggest that, during translocation of substrate polypeptides, the nonessential subunit Mgr2 seals the lateral opening of the Tim17 cavity to facilitate the translocation process. We propose a new model for the TIM23-mediated protein import and sorting mechanism, a central pathway in mitochondrial biogenesis. | |||
Structural basis of mitochondrial protein import by the TIM23 complex.,Sim SI, Chen Y, Lynch DL, Gumbart JC, Park E Nature. 2023 Sep;621(7979):620-626. doi: 10.1038/s41586-023-06239-6. Epub 2023 , Jun 21. PMID:37344598<ref>PMID:37344598</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
<div class="pdbe-citations 8e1m" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Mus musculus]] | |||
[[Category: Saccharomyces cerevisiae]] | |||
[[Category: Park E]] | |||
[[Category: Sim SI]] | |||
Latest revision as of 12:49, 9 October 2024
Cryo-EM structure of the endogenous core TIM23 complex from S. cerevisiaeCryo-EM structure of the endogenous core TIM23 complex from S. cerevisiae
Structural highlights
Publication Abstract from PubMedMitochondria import nearly all of their approximately 1,000-2,000 constituent proteins from the cytosol across their double-membrane envelope(1-5). Genetic and biochemical studies have shown that the conserved protein translocase, termed the TIM23 complex, mediates import of presequence-containing proteins (preproteins) into the mitochondrial matrix and inner membrane. Among about ten different subunits of the TIM23 complex, the essential multipass membrane protein Tim23, together with the evolutionarily related protein Tim17, has long been postulated to form a protein-conducting channel(6-11). However, the mechanism by which these subunits form a translocation path in the membrane and enable the import process remains unclear due to a lack of structural information. Here we determined the cryo-electron microscopy structure of the core TIM23 complex (heterotrimeric Tim17-Tim23-Tim44) from Saccharomyces cerevisiae. Contrary to the prevailing model, Tim23 and Tim17 themselves do not form a water-filled channel, but instead have separate, lipid-exposed concave cavities that face in opposite directions. Our structural and biochemical analyses show that the cavity of Tim17, but not Tim23, forms the protein translocation path, whereas Tim23 probably has a structural role. The results further suggest that, during translocation of substrate polypeptides, the nonessential subunit Mgr2 seals the lateral opening of the Tim17 cavity to facilitate the translocation process. We propose a new model for the TIM23-mediated protein import and sorting mechanism, a central pathway in mitochondrial biogenesis. Structural basis of mitochondrial protein import by the TIM23 complex.,Sim SI, Chen Y, Lynch DL, Gumbart JC, Park E Nature. 2023 Sep;621(7979):620-626. doi: 10.1038/s41586-023-06239-6. Epub 2023 , Jun 21. PMID:37344598[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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