+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-3926 | |||||||||
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Title | Nucleosome breathing : Class 8 | |||||||||
Map data | ||||||||||
Sample |
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Biological species | Xenopus laevis (African clawed frog) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 10.5 Å | |||||||||
Authors | Halic M / Bilokapic S | |||||||||
Citation | Journal: Nat Struct Mol Biol / Year: 2018 Title: Histone octamer rearranges to adapt to DNA unwrapping. Authors: Silvija Bilokapic / Mike Strauss / Mario Halic / Abstract: Nucleosomes, the basic units of chromatin, package and regulate expression of eukaryotic genomes. Although the structure of the intact nucleosome is well characterized, little is known about ...Nucleosomes, the basic units of chromatin, package and regulate expression of eukaryotic genomes. Although the structure of the intact nucleosome is well characterized, little is known about structures of partially unwrapped, transient intermediates. In this study, we present nine cryo-EM structures of distinct conformations of nucleosome and subnucleosome particles. These structures show that initial DNA breathing induces conformational changes in the histone octamer, particularly in histone H3, that propagate through the nucleosome and prevent symmetrical DNA opening. Rearrangements in the H2A-H2B dimer strengthen interaction with the unwrapping DNA and promote nucleosome stability. In agreement with this, cross-linked H2A-H2B that cannot accommodate unwrapping of the DNA is not stably maintained in the nucleosome. H2A-H2B release and DNA unwrapping occur simultaneously, indicating that DNA is essential in stabilizing the dimer in the nucleosome. Our structures reveal intrinsic nucleosomal plasticity that is required for nucleosome stability and might be exploited by extrinsic protein factors. | |||||||||
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_3926.map.gz | 11.8 MB | EMDB map data format | |
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Header (meta data) | emd-3926-v30.xml emd-3926.xml | 7.7 KB 7.7 KB | Display Display | EMDB header |
Images | emd_3926.png | 130.2 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-3926 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-3926 | HTTPS FTP |
-Validation report
Summary document | emd_3926_validation.pdf.gz | 195.8 KB | Display | EMDB validaton report |
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Full document | emd_3926_full_validation.pdf.gz | 195 KB | Display | |
Data in XML | emd_3926_validation.xml.gz | 5.7 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-3926 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-3926 | HTTPS FTP |
-Related structure data
Related structure data | 3925C 3929C 3930C 3931C 3947C 3948C 3949C 3950C 6esfC 6esgC 6eshC 6esiC C: citing same article (ref.) |
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Similar 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_3926.map.gz / Format: CCP4 / Size: 18.1 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: 1.4 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 : Nucleosome
Entire | Name: Nucleosome |
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Components |
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-Supramolecule #1: Nucleosome
Supramolecule | Name: Nucleosome / type: complex / ID: 1 / Parent: 0 |
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Source (natural) | Organism: Xenopus laevis (African clawed frog) |
Recombinant expression | Organism: Escherichia coli (E. coli) |
Molecular weight | Theoretical: 200 KDa |
-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 |
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Image recording | Film or detector model: FEI FALCON II (4k x 4k) / Detector mode: INTEGRATING / Average electron dose: 100.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD |
-Image processing
Startup model | Type of model: PDB ENTRY PDB model - PDB ID: |
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Final reconstruction | Resolution.type: BY AUTHOR / Resolution: 10.5 Å / Resolution method: FSC 0.143 CUT-OFF / Software - Name: RELION (ver. 1.4) / Number images used: 16000 |
Initial angle assignment | Type: PROJECTION MATCHING |
Final angle assignment | Type: PROJECTION MATCHING |