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Open data
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Basic information
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Title | MicroED structure of proteinase K recorded on K2 | |||||||||
![]() | 2mFo-DFc | |||||||||
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![]() | serine protease / HYDROLASE | |||||||||
Function / homology | ![]() peptidase K / serine-type endopeptidase activity / proteolysis / extracellular space / metal ion binding Similarity search - Function | |||||||||
Biological species | ![]() | |||||||||
Method | electron crystallography / cryo EM | |||||||||
![]() | Clabbers MTB / Martynowycz MW / Hattne J / Nannenga BL / Gonen T | |||||||||
Funding support | ![]()
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![]() | ![]() Title: Electron-counting MicroED data with the K2 and K3 direct electron detectors. Authors: Max T B Clabbers / Michael W Martynowycz / Johan Hattne / Brent L Nannenga / Tamir Gonen / ![]() Abstract: Microcrystal electron diffraction (MicroED) uses electron cryo-microscopy (cryo-EM) to collect diffraction data from small crystals during continuous rotation of the sample. As a result of advances ...Microcrystal electron diffraction (MicroED) uses electron cryo-microscopy (cryo-EM) to collect diffraction data from small crystals during continuous rotation of the sample. As a result of advances in hardware as well as methods development, the data quality has continuously improved over the past decade, to the point where even macromolecular structures can be determined ab initio. Detectors suitable for electron diffraction should ideally have fast readout to record data in movie mode, and high sensitivity at low exposure rates to accurately report the intensities. Direct electron detectors are commonly used in cryo-EM imaging for their sensitivity and speed, but despite their availability are generally not used in diffraction. Primary concerns with diffraction experiments are the dynamic range and coincidence loss, which will corrupt the measurement if the flux exceeds the count rate of the detector. Here, we describe instrument setup and low-exposure MicroED data collection in electron-counting mode using K2 and K3 direct electron detectors and show that the integrated intensities can be effectively used to solve structures of two macromolecules between 1.2 Å and 2.8 Å resolution. Even though a beam stop was not used with the K3 studies we did not observe damage to the camera. As these cameras are already available in many cryo-EM facilities, this provides opportunities for users who do not have access to dedicated facilities for MicroED. | |||||||||
History |
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Structure visualization
Supplemental images |
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Downloads & links
-EMDB archive
Map data | ![]() | 2 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 13.5 KB 13.5 KB | Display Display | ![]() |
Images | ![]() | 52.9 KB | ||
Filedesc metadata | ![]() | 5.5 KB | ||
Filedesc structureFactors | ![]() | 167.1 KB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 8e52MC ![]() 8e53C ![]() 8e54C M: atomic model generated by this map C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
EMDB pages | ![]() ![]() |
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Related items in Molecule of the Month |
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Map
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Annotation | 2mFo-DFc | ||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. generated in cubic-lattice coordinate | ||||||||||||||||||||||||||||||||||||
Voxel size | X: 0.6757 Å / Y: 0.6757 Å / Z: 0.6307 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
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Sample components
-Entire : Proteinase K
Entire | Name: Proteinase K |
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Components |
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-Supramolecule #1: Proteinase K
Supramolecule | Name: Proteinase K / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1 / Details: Serine protease |
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Source (natural) | Organism: ![]() |
Molecular weight | Theoretical: 28.9 KDa |
-Macromolecule #1: Proteinase K
Macromolecule | Name: Proteinase K / type: protein_or_peptide / ID: 1 / Number of copies: 1 / Enantiomer: LEVO / EC number: peptidase K |
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Source (natural) | Organism: ![]() |
Molecular weight | Theoretical: 28.930783 KDa |
Recombinant expression | Organism: ![]() |
Sequence | String: AAQTNAPWGL ARISSTSPGT STYYYDESAG QGSCVYVIDT GIEASHPEFE GRAQMVKTYY YSSRDGNGHG THCAGTVGSR TYGVAKKTQ LFGVKVLDDN GSGQYSTIIA GMDFVASDKN NRNCPKGVVA SLSLGGGYSS SVNSAAARLQ SSGVMVAVAA G NNNADARN ...String: AAQTNAPWGL ARISSTSPGT STYYYDESAG QGSCVYVIDT GIEASHPEFE GRAQMVKTYY YSSRDGNGHG THCAGTVGSR TYGVAKKTQ LFGVKVLDDN GSGQYSTIIA GMDFVASDKN NRNCPKGVVA SLSLGGGYSS SVNSAAARLQ SSGVMVAVAA G NNNADARN YSPASEPSVC TVGASDRYDR RSSFSNYGSV LDIFGPGTSI LSTWIGGSTR SISGTSMATP HVAGLAAYLM TL GKTTAAS ACRYIADTAN KGDLSNIPFG TVNLLAYNNY QA UniProtKB: Proteinase K |
-Macromolecule #2: CALCIUM ION
Macromolecule | Name: CALCIUM ION / type: ligand / ID: 2 / Number of copies: 4 / Formula: CA |
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Molecular weight | Theoretical: 40.078 Da |
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | electron crystallography |
Aggregation state | 3D array |
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Sample preparation
Concentration | 50 mg/mL |
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Buffer | pH: 8 |
Grid | Model: Quantifoil R2/1 / Material: COPPER / Mesh: 300 / Support film - Material: CARBON / Support film - topology: HOLEY / Support film - Film thickness: 10 |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 95 % / Chamber temperature: 277 K / Instrument: LEICA PLUNGER |
Details | Microcrystals |
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Electron microscopy
Microscope | FEI TITAN KRIOS |
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Temperature | Min: 77.0 K / Max: 90.0 K |
Image recording | Film or detector model: GATAN K2 BASE (4k x 4k) / Digitization - Dimensions - Width: 1650 pixel / Digitization - Dimensions - Height: 1470 pixel / Number grids imaged: 1 / Number real images: 1 / Number diffraction images: 1600 / Average exposure time: 0.025 sec. / Average electron dose: 0.01 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: ![]() |
Electron optics | C2 aperture diameter: 50.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: DIFFRACTION / Cs: 2.7 mm / Camera length: 590 mm |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Image processing
Final reconstruction | Resolution method: DIFFRACTION PATTERN/LAYERLINES / Software - Name: REFMAC |
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Merging software list | Software - Name: AIMLESS |
Crystallography statistics | Number intensities measured: 30326 / Number structure factors: 5453 / Fourier space coverage: 83 / R sym: 30 / R merge: 64 / Overall phase error: 28 / Overall phase residual: 0 / Phase error rejection criteria: None / High resolution: 2.7 Å / Shell - Shell ID: 1 / Shell - High resolution: 2.7 Å / Shell - Low resolution: 3.4 Å / Shell - Number structure factors: 2499 / Shell - Phase residual: 33 / Shell - Fourier space coverage: 83 / Shell - Multiplicity: 6 |
-Atomic model buiding 1
Refinement | Space: RECIPROCAL / Protocol: RIGID BODY FIT / Overall B value: 20.32 / Target criteria: Maximum liklihood |
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Output model | ![]() PDB-8e52: |