+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-14983 | |||||||||
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Title | Structure of b-galactosidase with TCEP prepared by Vitrobot | |||||||||
Map data | ||||||||||
Sample |
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Biological species | Escherichia coli (E. coli) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 2.4 Å | |||||||||
Authors | Klebl DP / Wang Y | |||||||||
Funding support | United Kingdom, 1 items
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Citation | Journal: Front Mol Biosci / Year: 2022 Title: It started with a Cys: Spontaneous cysteine modification during cryo-EM grid preparation. Authors: David P Klebl / Yiheng Wang / Frank Sobott / Rebecca F Thompson / Stephen P Muench / Abstract: Advances in single particle cryo-EM data collection and processing have seen a significant rise in its use. However, the influences of the environment generated through grid preparation, by for ...Advances in single particle cryo-EM data collection and processing have seen a significant rise in its use. However, the influences of the environment generated through grid preparation, by for example interactions of proteins with the air-water interface are poorly understood and can be a major hurdle in structure determination by cryo-EM. Initial interactions of proteins with the air-water interface occur quickly and proteins can adopt preferred orientation or partially unfold within hundreds of milliseconds. It has also been shown previously that thin-film layers create hydroxyl radicals. To investigate the potential this might have in cryo-EM sample preparation, we studied two proteins, HSPD1, and beta-galactosidase, and show that cysteine residues are modified in a time-dependent manner. In the case of both HSPD1 and beta-galactosidase, this putative oxidation is linked to partial protein unfolding, as well as more subtle structural changes. We show these modifications can be alleviated through increasing the speed of grid preparation, the addition of DTT, or by sequestering away from the AWI using continuous support films. We speculate that the modification is oxidation by reactive oxygen species which are formed and act at the air-water interface. Finally, we show grid preparation on a millisecond timescale outruns cysteine modification, showing that the reaction timescale is in the range of 100s to 1,000s milliseconds and offering an alternative approach to prevent spontaneous cysteine modification and its consequences during cryo-EM grid preparation. | |||||||||
History |
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-Structure visualization
Supplemental images |
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-Downloads & links
-EMDB archive
Map data | emd_14983.map.gz | 14.5 MB | EMDB map data format | |
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Header (meta data) | emd-14983-v30.xml emd-14983.xml | 12.4 KB 12.4 KB | Display Display | EMDB header |
FSC (resolution estimation) | emd_14983_fsc.xml | 12.7 KB | Display | FSC data file |
Images | emd_14983.png | 62.7 KB | ||
Others | emd_14983_half_map_1.map.gz emd_14983_half_map_2.map.gz | 139 MB 139.2 MB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-14983 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-14983 | HTTPS FTP |
-Validation report
Summary document | emd_14983_validation.pdf.gz | 739.4 KB | Display | EMDB validaton report |
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Full document | emd_14983_full_validation.pdf.gz | 738.9 KB | Display | |
Data in XML | emd_14983_validation.xml.gz | 20.4 KB | Display | |
Data in CIF | emd_14983_validation.cif.gz | 26.8 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-14983 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-14983 | HTTPS FTP |
-Related structure data
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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-Map
File | Download / File: emd_14983.map.gz / Format: CCP4 / Size: 178 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.86 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Half map: #1
File | emd_14983_half_map_1.map | ||||||||||||
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Projections & Slices |
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Density Histograms |
-Half map: #2
File | emd_14983_half_map_2.map | ||||||||||||
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Projections & Slices |
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Density Histograms |
-Sample components
-Entire : Blotted b-galactosidase with TCEP
Entire | Name: Blotted b-galactosidase with TCEP |
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Components |
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-Supramolecule #1: Blotted b-galactosidase with TCEP
Supramolecule | Name: Blotted b-galactosidase with TCEP / type: complex / Chimera: Yes / ID: 1 / Parent: 0 |
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Source (natural) | Organism: Escherichia coli (E. coli) |
Recombinant expression | Organism: Escherichia coli (E. coli) |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 1 mg/mL |
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Buffer | pH: 8 |
Grid | Model: Quantifoil R1.2/1.3 / Material: COPPER / Mesh: 300 / Support film - Material: CARBON / Support film - topology: HOLEY ARRAY / Pretreatment - Type: GLOW DISCHARGE |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 95 % / 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: FEI FALCON IV (4k x 4k) / Average electron dose: 37.9 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 2.0 µm / Nominal defocus min: 0.8 µm |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |