+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-23632 | |||||||||
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Title | cryo-EM density map of canonical nucleosome | |||||||||
Map data | Canonical nucleosome | |||||||||
Sample |
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Function / homology | Function and homology information RNA polymerase II core promoter sequence-specific DNA binding / heterochromatin / nucleosomal DNA binding / cellular response to estradiol stimulus / euchromatin / cellular response to insulin stimulus / heterochromatin formation / structural constituent of chromatin / nucleosome / nucleosome assembly ...RNA polymerase II core promoter sequence-specific DNA binding / heterochromatin / nucleosomal DNA binding / cellular response to estradiol stimulus / euchromatin / cellular response to insulin stimulus / heterochromatin formation / structural constituent of chromatin / nucleosome / nucleosome assembly / chromatin organization / RNA polymerase II cis-regulatory region sequence-specific DNA binding / protein heterodimerization activity / positive regulation of transcription by RNA polymerase II / DNA binding / nucleus Similarity search - Function | |||||||||
Biological species | Xenopus laevis (African clawed frog) / unidentified (others) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 3.8 Å | |||||||||
Authors | Lewis T / Sokolova V / Ng H / Tan D | |||||||||
Funding support | United States, 2 items
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Citation | Journal: Nucleic Acids Res / Year: 2021 Title: Structural basis of chromatin regulation by histone variant H2A.Z. Authors: Tyler S Lewis / Vladyslava Sokolova / Harry Jung / Honkit Ng / Dongyan Tan / Abstract: The importance of histone variant H2A.Z in transcription regulation has been well established, yet its mechanism-of-action remains enigmatic. Conflicting evidence exists in support of both an ...The importance of histone variant H2A.Z in transcription regulation has been well established, yet its mechanism-of-action remains enigmatic. Conflicting evidence exists in support of both an activating and a repressive role of H2A.Z in transcription. Here we report cryo-electron microscopy (cryo-EM) structures of nucleosomes and chromatin fibers containing H2A.Z and those containing canonical H2A. The structures show that H2A.Z incorporation results in substantial structural changes in both nucleosome and chromatin fiber. While H2A.Z increases the mobility of DNA terminus in nucleosomes, it simultaneously enables nucleosome arrays to form a more regular and condensed chromatin fiber. We also demonstrated that H2A.Z's ability to enhance nucleosomal DNA mobility is largely attributed to its characteristic shorter C-terminus. Our study provides the structural basis for H2A.Z-mediated chromatin regulation, showing that the increase flexibility of the DNA termini in H2A.Z nucleosomes is central to its dual-functions in chromatin regulation and in transcription. | |||||||||
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_23632.map.gz | 26.7 MB | EMDB map data format | |
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Header (meta data) | emd-23632-v30.xml emd-23632.xml | 20.8 KB 20.8 KB | Display Display | EMDB header |
FSC (resolution estimation) | emd_23632_fsc.xml | 6.9 KB | Display | FSC data file |
Images | emd_23632.png | 82.2 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-23632 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-23632 | HTTPS FTP |
-Validation report
Summary document | emd_23632_validation.pdf.gz | 334.6 KB | Display | EMDB validaton report |
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Full document | emd_23632_full_validation.pdf.gz | 334.2 KB | Display | |
Data in XML | emd_23632_validation.xml.gz | 9.2 KB | Display | |
Data in CIF | emd_23632_validation.cif.gz | 11.7 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-23632 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-23632 | 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_23632.map.gz / Format: CCP4 / Size: 30.5 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | Canonical nucleosome | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.12 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 containing canonical histones H2A, H2B, H3 and H4
+Supramolecule #1: Nucleosome containing canonical histones H2A, H2B, H3 and H4
+Supramolecule #2: Histones H2A
+Supramolecule #3: 167-bp 601 Widom DNA sequence
+Supramolecule #4: Histone H2B
+Supramolecule #5: Histone H3
+Supramolecule #6: Histone H4
+Macromolecule #1: Histone H2A
+Macromolecule #2: Histone H2B
+Macromolecule #3: Histone H3
+Macromolecule #4: Histone H4
+Macromolecule #5: 167-bp 601 Widom DNA sequence
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 1 mg/mL | |||||||||||||||
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Buffer | pH: 8 Component:
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Grid | Model: Quantifoil R1.2/1.3 / Material: COPPER / Mesh: 400 / Support film - Material: CARBON / Support film - topology: HOLEY / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Atmosphere: AIR | |||||||||||||||
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277.15 K / Instrument: FEI VITROBOT MARK IV Details: Grid was blotted for 5 seconds before plunge freezing. |
-Electron microscopy
Microscope | FEI TALOS ARCTICA |
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Image recording | Film or detector model: FEI FALCON III (4k x 4k) / Detector mode: COUNTING / Number grids imaged: 2 / Number real images: 1970 / Average exposure time: 60.0 sec. / Average electron dose: 33.0 e/Å2 |
Electron beam | Acceleration voltage: 200 kV / Electron source: FIELD EMISSION GUN |
Electron optics | C2 aperture diameter: 100.0 µm / Calibrated magnification: 123811 / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 2.5 µm / Nominal defocus min: 0.9 µm / Nominal magnification: 92000 |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
Experimental equipment | Model: Talos Arctica / Image courtesy: FEI Company |