+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-8747 | |||||||||
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Title | Cryo-EM reconstruction of the HO microcompartment shell | |||||||||
Map data | Cryo-EM reconstruction of the HO microcompartment shell | |||||||||
Sample |
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Function / homology | Function and homology information | |||||||||
Biological species | Haliangium ochraceum (bacteria) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 8.7 Å | |||||||||
Authors | Sutter M / Greber BJ / Aussignargues C / Kerfeld CA | |||||||||
Citation | Journal: Science / Year: 2017 Title: Assembly principles and structure of a 6.5-MDa bacterial microcompartment shell. Authors: Markus Sutter / Basil Greber / Clement Aussignargues / Cheryl A Kerfeld / Abstract: Many bacteria contain primitive organelles composed entirely of protein. These bacterial microcompartments share a common architecture of an enzymatic core encapsulated in a selectively permeable ...Many bacteria contain primitive organelles composed entirely of protein. These bacterial microcompartments share a common architecture of an enzymatic core encapsulated in a selectively permeable protein shell; prominent examples include the carboxysome for CO fixation and catabolic microcompartments found in many pathogenic microbes. The shell sequesters enzymatic reactions from the cytosol, analogous to the lipid-based membrane of eukaryotic organelles. Despite available structural information for single building blocks, the principles of shell assembly have remained elusive. We present the crystal structure of an intact shell from , revealing the basic principles of bacterial microcompartment shell construction. Given the conservation among shell proteins of all bacterial microcompartments, these principles apply to functionally diverse organelles and can inform the design and engineering of shells with new functionalities. | |||||||||
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_8747.map.gz | 6.6 MB | EMDB map data format | |
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Header (meta data) | emd-8747-v30.xml emd-8747.xml | 14.4 KB 14.4 KB | Display Display | EMDB header |
Images | emd_8747.png | 261.6 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-8747 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-8747 | HTTPS FTP |
-Related 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_8747.map.gz / Format: CCP4 / Size: 27 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | Cryo-EM reconstruction of the HO microcompartment shell | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 2.8 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 : BMC (bacterial microcompartment) shell
Entire | Name: BMC (bacterial microcompartment) shell |
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Components |
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-Supramolecule #1: BMC (bacterial microcompartment) shell
Supramolecule | Name: BMC (bacterial microcompartment) shell / type: complex / ID: 1 / Parent: 0 |
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Source (natural) | Organism: Haliangium ochraceum (bacteria) |
Recombinant expression | Organism: Escherichia coli (E. coli) / Recombinant strain: BL21 (DE3) |
Molecular weight | Theoretical: 6.5 MDa |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 3 mg/mL | ||||||||||||
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Buffer | pH: 7.4 Component:
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Grid | Model: Protochips CF-1.2/1.3 / Material: COPPER / Mesh: 400 / Support film - #0 - Film type ID: 1 / Support film - #0 - Material: CARBON / Support film - #0 - topology: HOLEY / Support film - #1 - Film type ID: 2 / Support film - #1 - Material: CARBON / Support film - #1 - topology: CONTINUOUS / Pretreatment - Type: PLASMA CLEANING | ||||||||||||
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K / Instrument: FEI VITROBOT MARK IV / Details: Incubation on grid for 5-7 sec before plunging. |
-Electron microscopy
Microscope | FEI TECNAI F20 |
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Electron beam | Acceleration voltage: 120 kV / Electron source: FIELD EMISSION GUN |
Electron optics | C2 aperture diameter: 100.0 µm / Calibrated magnification: 107142 / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELDBright-field microscopy / Cs: 2.2 mm / Nominal defocus max: 3.0 µm / Nominal defocus min: 1.5 µm / Nominal magnification: 100000 |
Sample stage | Specimen holder model: GATAN 626 SINGLE TILT LIQUID NITROGEN CRYO TRANSFER HOLDER Cooling holder cryogen: NITROGEN |
Image recording | Film or detector model: GATAN ULTRASCAN 4000 (4k x 4k) / Digitization - Dimensions - Width: 4096 pixel / Digitization - Dimensions - Height: 4096 pixel / Digitization - Sampling interval: 15.0 µm / Number grids imaged: 1 / Number real images: 90 / Average exposure time: 0.4 sec. / Average electron dose: 25.0 e/Å2 / Details: Semi-automated collection using LEGINON |
Experimental equipment | Model: Tecnai F20 / Image courtesy: FEI Company |
-Image processing
Particle selection | Number selected: 3750 |
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CTF correction | Software - Name: CTFFIND (ver. 4) / Details: CTF correction was performed inside RELION 1.4 |
Startup model | Type of model: EMDB MAP EMDB ID: Details: EMD-3351 was scaled to match the size of the BMC shell and low-pass filtered to avoid model bias. |
Initial angle assignment | Type: OTHER / Software - Name: RELION (ver. 1.4) Details: Initial angle assignment during RELION 3D auto-refinement (maximum likelihood) based on initial reference. Icosahedral symmetry was imposed. |
Final 3D classification | Number classes: 4 / Software - Name: RELION (ver. 1.4) Details: 3450 particle images were classified into 4 classes in RELION 1.4. Two classes (approx. 2600 particles) were included in the final refinement. Icosahedral symmetry was imposed during classification. |
Final angle assignment | Type: OTHER / Software - Name: RELION (ver. 1.4) Details: RELION 3D auto-refinement (maximum likelihood, gold standard). Icosahedral symmetry was imposed. |
Final reconstruction | Number classes used: 2 / Applied symmetry - Point group: I (icosahedral) / Resolution.type: BY AUTHOR / Resolution: 8.7 Å / Resolution method: FSC 0.143 CUT-OFF / Software - Name: RELION (ver. 1.4) / Details: Icosahedral symmetry was imposed. / Number images used: 2600 |
-Atomic model buiding 1
Initial model |
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Details | Existing high-resolution structures, truncated to poly-alanines, were docked into the map to create a model for molecular replacement phasing of BMC shell X-ray diffraction data. | ||||||||
Refinement | Space: REAL / Protocol: RIGID BODY FIT |