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Yorodumi- EMDB-2221: GroEL at sub-nanometer resolution by Constrained Single Particle ... -
+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-2221 | |||||||||
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Title | GroEL at sub-nanometer resolution by Constrained Single Particle Tomography | |||||||||
Map data | Reconstruction of GroEL | |||||||||
Sample |
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Function / homology | Function and homology information GroEL-GroES complex / chaperonin ATPase / chaperone cofactor-dependent protein refolding / isomerase activity / ATP-dependent protein folding chaperone / unfolded protein binding / response to heat / protein refolding / ATP binding Similarity search - Function | |||||||||
Biological species | Escherichia coli UTI89 (bacteria) | |||||||||
Method | subtomogram averaging / cryo EM / Resolution: 8.4 Å | |||||||||
Authors | Bartesaghi A / Lecumberry F / Sapiro G / Subramaniam S | |||||||||
Citation | Journal: Structure / Year: 2012 Title: Protein secondary structure determination by constrained single-particle cryo-electron tomography. Authors: Alberto Bartesaghi / Federico Lecumberry / Guillermo Sapiro / Sriram Subramaniam / Abstract: Cryo-electron microscopy (cryo-EM) is a powerful technique for 3D structure determination of protein complexes by averaging information from individual molecular images. The resolutions that can be ...Cryo-electron microscopy (cryo-EM) is a powerful technique for 3D structure determination of protein complexes by averaging information from individual molecular images. The resolutions that can be achieved with single-particle cryo-EM are frequently limited by inaccuracies in assigning molecular orientations based solely on 2D projection images. Tomographic data collection schemes, however, provide powerful constraints that can be used to more accurately determine molecular orientations necessary for 3D reconstruction. Here, we propose "constrained single-particle tomography" as a general strategy for 3D structure determination in cryo-EM. A key component of our approach is the effective use of images recorded in tilt series to extract high-resolution information and correct for the contrast transfer function. By incorporating geometric constraints into the refinement to improve orientational accuracy of images, we reduce model bias and overrefinement artifacts and demonstrate that protein structures can be determined at resolutions of ∼8 Å starting from low-dose tomographic tilt series. | |||||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | EM map: SurfViewMolmilJmol/JSmol |
Supplemental images |
-Downloads & links
-EMDB archive
Map data | emd_2221.map.gz | 19.9 MB | EMDB map data format | |
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Header (meta data) | emd-2221-v30.xml emd-2221.xml | 11.9 KB 11.9 KB | Display Display | EMDB header |
Images | emd_2221.png | 985.6 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-2221 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-2221 | HTTPS FTP |
-Validation report
Summary document | emd_2221_validation.pdf.gz | 270.1 KB | Display | EMDB validaton report |
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Full document | emd_2221_full_validation.pdf.gz | 269.2 KB | Display | |
Data in XML | emd_2221_validation.xml.gz | 5.7 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-2221 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-2221 | HTTPS FTP |
-Related structure data
Related structure data | 2ynjMC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_2221.map.gz / Format: CCP4 / Size: 21.7 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | Reconstruction of GroEL | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.74 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
-Sample components
-Entire : GroEL
Entire | Name: GroEL |
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Components |
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-Supramolecule #1000: GroEL
Supramolecule | Name: GroEL / type: sample / ID: 1000 / Oligomeric state: 14-mer / Number unique components: 1 |
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Molecular weight | Theoretical: 800 KDa |
-Macromolecule #1: GroEL
Macromolecule | Name: GroEL / type: protein_or_peptide / ID: 1 / Number of copies: 1 / Oligomeric state: 14-mer / Recombinant expression: Yes |
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Source (natural) | Organism: Escherichia coli UTI89 (bacteria) |
Molecular weight | Theoretical: 800 KDa |
Recombinant expression | Organism: Escherichia coli (E. coli) |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | subtomogram averaging |
Aggregation state | particle |
-Sample preparation
Concentration | 3 mg/mL |
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Buffer | pH: 7.5 Details: 100 mM Hepes, pH 7.5, 10 mM Mg(OAc)2, 10 mM KOAc, 2 mM DTT |
Grid | Details: 400 mesh C-flat, 2um hole size (CF/2/2 grids), plasma cleaned for 6s with a Gatan Solarus plasma cleaner. |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 93 K / Instrument: FEI VITROBOT MARK IV / Method: Blot for 4 seconds before plunging |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Temperature | Min: 80 K / Max: 93 K / Average: 80 K |
Alignment procedure | Legacy - Astigmatism: Astigmatism corrected at 76000x |
Details | The total dose of 25 (electrons/square Angstrom) was fractionated evenly across 11 tilted projections taken between 0 and -20 degrees tilt (every 2 degrees). |
Date | Oct 7, 2011 |
Image recording | Category: CCD / Film or detector model: GENERIC CCD / Number real images: 1595 / Average electron dose: 25 e/Å2 Details: The 1595 micrographs corresponded to 145 tilt-series each containing 11 projections with tilt-angles between 0 and -20 degrees (every 2-degrees). Bits/pixel: 16 |
Electron beam | Acceleration voltage: 80 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Calibrated magnification: 47000 / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 3.0 µm / Nominal defocus min: 2.0 µm / Nominal magnification: 47000 |
Sample stage | Specimen holder: Nitrogen cooled / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Tilt series - Axis1 - Min angle: -20 ° / Tilt series - Axis1 - Max angle: 0 ° |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
Details | Particles were manually selected in 3D from reconstructed tomograms and their corresponding raw 2D projections extracted for further processing using Constrained Single Particle Tomography. Average number of projections used in the 3D reconstructions: 10000. |
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Final reconstruction | Algorithm: OTHER / Resolution.type: BY AUTHOR / Resolution: 8.4 Å / Resolution method: FSC 0.5 CUT-OFF / Software - Name: FREALIGN Details: Final map was amplitude corrected with BSOFT's command 'bampweight' using a density map generated from the PDB ID 3e76 coordinates as a reference. |
CTF correction | Details: Defocus values were assigned to each particle projection based on the defocus at the untilted plane of each tilt-series and a correction according to the relative height of each particle. to this plane |
Final angle assignment | Details: FREALIGN |
-Atomic model buiding 1
Initial model | PDB ID: Chain - Chain ID: H |
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Software | Name: Chimera |
Details | Protocol: Rigid body. Coordinates of chain H from 3e76 were fit using D7-symmetric fitting operation in Chimera. |
Refinement | Space: REAL / Protocol: RIGID BODY FIT / Target criteria: Correlation |
Output model | PDB-2ynj: |