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Open data
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Basic information
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Title | Structure of proteinase K from energy-filtered MicroED data | ||||||||||||
![]() | MicroED 2mFo-DFc map of proteinase K | ||||||||||||
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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 / Resolution: 1.09 Å | ||||||||||||
![]() | Clabbers MTB / Hattne J / Martynoqycz MW / Gonen T | ||||||||||||
Funding support | ![]()
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![]() | ![]() Title: Energy filtering enables macromolecular MicroED data at sub-atomic resolution. Authors: Max T B Clabbers / Johan Hattne / Michael W Martynowycz / Tamir Gonen / ![]() Abstract: High resolution information is important for accurate structure modelling. However, this level of detail is typically difficult to attain in macromolecular crystallography because the diffracted ...High resolution information is important for accurate structure modelling. However, this level of detail is typically difficult to attain in macromolecular crystallography because the diffracted intensities rapidly fade with increasing resolution. The problem cannot be circumvented by increasing the fluence as this leads to detrimental radiation damage. Previously, we demonstrated that high quality MicroED data can be obtained at low flux conditions using electron counting with direct electron detectors. The improved sensitivity and accuracy of these detectors essentially eliminate the read-out noise, such that the measurement of faint high-resolution reflections is limited by other sources of noise. Inelastic scattering is a major contributor of such noise, increasing background counts and broadening diffraction spots. Here, we demonstrate that a substantial improvement in signal-to-noise ratio can be achieved using an energy filter to largely remove the inelastically scattered electrons. This strategy resulted in sub-atomic resolution MicroED data from proteinase K crystals, enabling accurate structure modelling and the visualization of detailed features. Interestingly, filtering out the noise revealed diffuse scattering phenomena that can hold additional structural information. Our findings suggest that combining energy filtering and electron counting can provide more accurate measurements at higher resolution, providing better insights into protein function and facilitating more precise model refinement. | ||||||||||||
History |
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Structure visualization
Supplemental images |
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Downloads & links
-EMDB archive
Map data | ![]() | 36.4 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 16.2 KB 16.2 KB | Display Display | ![]() |
Images | ![]() | 542 KB | ||
Filedesc metadata | ![]() | 6.4 KB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 9dhoMC 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 | MicroED 2mFo-DFc map of proteinase K | ||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. generated in cubic-lattice coordinate | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.2677 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: 28.958791 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 LDIFGPGTDI 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: 2 / Formula: CA |
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Molecular weight | Theoretical: 40.078 Da |
-Macromolecule #3: NITRATE ION
Macromolecule | Name: NITRATE ION / type: ligand / ID: 3 / Number of copies: 1 / Formula: NO3 |
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Molecular weight | Theoretical: 62.005 Da |
Chemical component information | ![]() ChemComp-NO3: |
-Macromolecule #4: water
Macromolecule | Name: water / type: ligand / ID: 4 / Number of copies: 334 / Formula: HOH |
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Molecular weight | Theoretical: 18.015 Da |
Chemical component information | ![]() ChemComp-HOH: |
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | electron crystallography |
Aggregation state | 3D array |
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Sample preparation
Concentration | 40 mg/mL |
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Buffer | pH: 6.5 |
Grid | Model: Quantifoil R2/2 / Material: COPPER / Mesh: 200 / Support film - Material: CARBON / Support film - topology: HOLEY / Support film - Film thickness: 10 / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 60 sec. / Details: Negative 15 mA |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 95 % / Chamber temperature: 277 K / Instrument: LEICA PLUNGER |
Details | Microcrystals |
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Electron microscopy
Microscope | TFS KRIOS |
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Temperature | Min: 77.0 K / Max: 90.0 K |
Specialist optics | Energy filter - Name: TFS Selectris / Energy filter - Slit width: 10 eV |
Image recording | Film or detector model: FEI FALCON IV (4k x 4k) / Digitization - Dimensions - Width: 4096 pixel / Digitization - Dimensions - Height: 4096 pixel / Number grids imaged: 1 / Number real images: 1 / Number diffraction images: 420 / Average exposure time: 1.0 sec. / Average electron dose: 0.002 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 / Nominal defocus max: 0.0 µm / Nominal defocus min: 0.0 µm / Camera length: 1402 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
-Atomic model buiding 1
Initial model | PDB ID: Chain - Source name: PDB / Chain - Initial model type: experimental model / Details: Molecular replacement |
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Refinement | Space: RECIPROCAL / Protocol: OTHER / Overall B value: 11.29 / Target criteria: Maximum likelihood |
Output model | ![]() PDB-9dho: |