+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-21570 | |||||||||
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Title | 30S-Inactive-high-Mg2+ Class B | |||||||||
Map data | 30S-Inactive-high-Mg2+ Class B | |||||||||
Sample |
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Function / homology | Function and homology information ornithine decarboxylase inhibitor activity / transcription antitermination factor activity, RNA binding / misfolded RNA binding / Group I intron splicing / RNA folding / four-way junction DNA binding / negative regulation of translational initiation / regulation of mRNA stability / mRNA regulatory element binding translation repressor activity / positive regulation of RNA splicing ...ornithine decarboxylase inhibitor activity / transcription antitermination factor activity, RNA binding / misfolded RNA binding / Group I intron splicing / RNA folding / four-way junction DNA binding / negative regulation of translational initiation / regulation of mRNA stability / mRNA regulatory element binding translation repressor activity / positive regulation of RNA splicing / transcription elongation factor complex / regulation of DNA-templated transcription elongation / DNA endonuclease activity / transcription antitermination / DNA-templated transcription termination / maintenance of translational fidelity / mRNA 5'-UTR binding / ribosomal small subunit biogenesis / small ribosomal subunit rRNA binding / ribosome biogenesis / regulation of translation / ribosomal small subunit assembly / small ribosomal subunit / cytosolic small ribosomal subunit / cytoplasmic translation / tRNA binding / molecular adaptor activity / rRNA binding / ribosome / structural constituent of ribosome / translation / response to antibiotic / mRNA binding / RNA binding / zinc ion binding / cytosol / cytoplasm Similarity search - Function | |||||||||
Biological species | Escherichia coli K-12 (bacteria) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 4.5 Å | |||||||||
Authors | Ortega J | |||||||||
Funding support | Canada, 1 items
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Citation | Journal: RNA / Year: 2020 Title: Alternative conformations and motions adopted by 30S ribosomal subunits visualized by cryo-electron microscopy. Authors: Dushyant Jahagirdar / Vikash Jha / Kaustuv Basu / Josue Gomez-Blanco / Javier Vargas / Joaquin Ortega / Abstract: It is only after recent advances in cryo-electron microscopy that it is now possible to describe at high-resolution structures of large macromolecules that do not crystalize. Purified 30S subunits ...It is only after recent advances in cryo-electron microscopy that it is now possible to describe at high-resolution structures of large macromolecules that do not crystalize. Purified 30S subunits interconvert between an "active" and "inactive" conformation. The active conformation was described by crystallography in the early 2000s, but the structure of the inactive form at high resolution remains unsolved. Here we used cryo-electron microscopy to obtain the structure of the inactive conformation of the 30S subunit to 3.6 Å resolution and study its motions. In the inactive conformation, an alternative base-pairing of three nucleotides causes the region of helix 44, forming the decoding center to adopt an unlatched conformation and the 3' end of the 16S rRNA positions similarly to the mRNA during translation. Incubation of inactive 30S subunits at 42°C reverts these structural changes. The air-water interface to which ribosome subunits are exposed during sample preparation also peel off some ribosomal proteins. Extended exposures to low magnesium concentrations make the ribosomal particles more susceptible to the air-water interface causing the unfolding of large rRNA structural domains. Overall, this study provides new insights about the conformational space explored by the 30S ribosomal subunit when the ribosomal particles are free in solution. | |||||||||
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_21570.map.gz | 100.3 MB | EMDB map data format | |
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Header (meta data) | emd-21570-v30.xml emd-21570.xml | 11.4 KB 11.4 KB | Display Display | EMDB header |
FSC (resolution estimation) | emd_21570_fsc.xml | 10.9 KB | Display | FSC data file |
Images | emd_21570.png | 103.2 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-21570 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-21570 | HTTPS FTP |
-Validation report
Summary document | emd_21570_validation.pdf.gz | 77.8 KB | Display | EMDB validaton report |
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Full document | emd_21570_full_validation.pdf.gz | 76.9 KB | Display | |
Data in XML | emd_21570_validation.xml.gz | 494 B | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-21570 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-21570 | 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_21570.map.gz / Format: CCP4 / Size: 107.2 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | 30S-Inactive-high-Mg2+ Class B | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.073 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 : 30S-Inactive-high-Mg2+ Class B
Entire | Name: 30S-Inactive-high-Mg2+ Class B |
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Components |
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-Supramolecule #1: 30S-Inactive-high-Mg2+ Class B
Supramolecule | Name: 30S-Inactive-high-Mg2+ Class B / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1-#18 |
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Source (natural) | Organism: Escherichia coli K-12 (bacteria) |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Buffer | pH: 7.4 |
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Vitrification | Cryogen name: ETHANE |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: FEI FALCON II (4k x 4k) / Detector mode: INTEGRATING / Average electron dose: 52.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
+Image processing
-Atomic model buiding 1
Initial model | PDB ID: |
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Refinement | Space: REAL |