+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-40346 | |||||||||
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Title | Cryo-EM structure of the core TIM23 complex from S. cerevisiae | |||||||||
Map data | Summed, sharpened map | |||||||||
Sample |
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Keywords | TRANSLOCASE | |||||||||
Function / homology | Function and homology information TIM23 mitochondrial import inner membrane translocase complex / protein import into mitochondrial matrix / protein transmembrane transporter activity / protein-folding chaperone binding / mitochondrial inner membrane Similarity search - Function | |||||||||
Biological species | Saccharomyces cerevisiae (brewer's yeast) / Mus musculus (house mouse) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 2.7 Å | |||||||||
Authors | Sim SI / Park E | |||||||||
Funding support | United States, 1 items
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Citation | Journal: Nature / Year: 2023 Title: Structural basis of mitochondrial protein import by the TIM23 complex. Authors: Sue Im Sim / Yuanyuan Chen / Diane L Lynch / James C Gumbart / Eunyong Park / Abstract: Mitochondria import nearly all of their approximately 1,000-2,000 constituent proteins from the cytosol across their double-membrane envelope. Genetic and biochemical studies have shown that the ...Mitochondria import nearly all of their approximately 1,000-2,000 constituent proteins from the cytosol across their double-membrane envelope. 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. 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. | |||||||||
History |
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-Structure visualization
Supplemental images |
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-Downloads & links
-EMDB archive
Map data | emd_40346.map.gz | 104.7 MB | EMDB map data format | |
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Header (meta data) | emd-40346-v30.xml emd-40346.xml | 24.6 KB 24.6 KB | Display Display | EMDB header |
FSC (resolution estimation) | emd_40346_fsc.xml | 12.1 KB | Display | FSC data file |
Images | emd_40346.png | 83.1 KB | ||
Filedesc metadata | emd-40346.cif.gz | 6.8 KB | ||
Others | emd_40346_additional_1.map.gz emd_40346_half_map_1.map.gz emd_40346_half_map_2.map.gz | 63.1 MB 116.2 MB 116.2 MB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-40346 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-40346 | HTTPS FTP |
-Validation report
Summary document | emd_40346_validation.pdf.gz | 800 KB | Display | EMDB validaton report |
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Full document | emd_40346_full_validation.pdf.gz | 799.5 KB | Display | |
Data in XML | emd_40346_validation.xml.gz | 19.1 KB | Display | |
Data in CIF | emd_40346_validation.cif.gz | 24.2 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-40346 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-40346 | HTTPS FTP |
-Related structure data
Related structure data | 8scxMC 8e1mC 24886 M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_40346.map.gz / Format: CCP4 / Size: 125 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||
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Annotation | Summed, sharpened map | ||||||||||||||||||||
Voxel size | X=Y=Z: 1.05 Å | ||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Additional map: Summed, unsharpened map
File | emd_40346_additional_1.map | ||||||||||||
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Annotation | Summed, unsharpened map | ||||||||||||
Projections & Slices |
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Density Histograms |
-Half map: Half map 1
File | emd_40346_half_map_1.map | ||||||||||||
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Annotation | Half map 1 | ||||||||||||
Projections & Slices |
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Density Histograms |
-Half map: Half map 2
File | emd_40346_half_map_2.map | ||||||||||||
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Annotation | Half map 2 | ||||||||||||
Projections & Slices |
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Density Histograms |
-Sample components
+Entire : Core TIM23 complex (core+Pam16/18)
+Supramolecule #1: Core TIM23 complex (core+Pam16/18)
+Supramolecule #2: Mitochondrial import inner membrane translocase subunit TIM17, Mi...
+Supramolecule #3: Antibody Fab fragment light chain, Antibody Fab fragment heavy chain
+Macromolecule #1: Mitochondrial import inner membrane translocase subunit TIM17
+Macromolecule #2: Mitochondrial import inner membrane translocase subunit TIM23
+Macromolecule #3: Mitochondrial import inner membrane translocase subunit TIM44
+Macromolecule #4: Antibody Fab fragment light chain
+Macromolecule #5: Antibody Fab fragment heavy chain
+Macromolecule #6: CARDIOLIPIN
+Macromolecule #7: PHOSPHATIDYLETHANOLAMINE
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Buffer | pH: 7.5 |
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Grid | Model: Quantifoil R1.2/1.3 / Material: GOLD / Mesh: 400 / Support film - Material: CARBON / Support film - topology: HOLEY / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 40 sec. / Pretreatment - Atmosphere: AIR / Pretreatment - Pressure: 0.039 kPa |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K / Instrument: FEI VITROBOT MARK IV |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K3 (6k x 4k) / Average electron dose: 50.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 2.1 µm / Nominal defocus min: 0.8 µm |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |