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Open data
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Basic information
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| Title | gamma-H2AX containing nucleosome bound to MDC1 BRCT | |||||||||
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Keywords | phosphorylation / nucleosome / NUCLEAR PROTEIN / BRCT / DNA BINDING PROTEIN | |||||||||
| Biological species | Homo sapiens (human) | |||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 2.7 Å | |||||||||
Authors | Panigrahi R / Edwards R / Glover JNM | |||||||||
| Funding support | Canada, 1 items
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Citation | Journal: Nucleic Acids Res / Year: 2025Title: Structural insights into γH2Ax containing nucleosomes. Authors: Rashmi Panigrahi / Ross Edwards / Md Touhidul Islam / Jun Lu / Ayodeji Kulepa / Tae Hwan Kim / J N Mark Glover / ![]() Abstract: The phosphorylation of the histone variant H2AX on the nucleosome, yielding γH2AX, acts as a 'master control switch', signaling the recruitment of DNA repair factors at DNA double-stranded break ...The phosphorylation of the histone variant H2AX on the nucleosome, yielding γH2AX, acts as a 'master control switch', signaling the recruitment of DNA repair factors at DNA double-stranded break sites. This phosphorylation is recognized by BRCA1 carboxy-terminal (BRCT) domains of specific repair proteins. Using cryogenic electron microscopy (cryo-EM), we provide structural insights into diverse mononucleosome architectures and inter-nucleosomal interactions in the presence of H2AX, mimicking nucleosomes during DNA repair. We resolved three distinct stacked structures where the nucleosomal dyad axes and disk planes align parallel. The inter-nucleosomal interactions involve unique contacts mediated by the H4 N-terminal tail, exposed H2B elements, and DNA. Geometric analysis of stacking constraints, including published structures, reveals a tight distribution of rotational parameters around 0o, with the greatest variability in the translational parameter 'slide'. Our studies indicate that phosphorylation-dependent binding of BRCT domains with γH2AX nucleosomes disrupts stacking. However, no clear densities for BRCT proteins were observed, indicative of dynamic interactions. Molecular simulations replicate the stability of BRCT binding to γH2AX but do not indicate stable docked conformations of BRCT to nucleosome. We propose that BRCT recognition of γH2AX nucleosomes could contribute to chromatin decondensation during DNA damage signaling, exposing the nucleosomal acidic patch for repair factor recognition. | |||||||||
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Structure visualization
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Downloads & links
-EMDB archive
| Map data | emd_48547.map.gz | 62.8 MB | EMDB map data format | |
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| Header (meta data) | emd-48547-v30.xml emd-48547.xml | 11.9 KB 11.9 KB | Display Display | EMDB header |
| FSC (resolution estimation) | emd_48547_fsc.xml | 10.5 KB | Display | FSC data file |
| Images | emd_48547.png | 109.9 KB | ||
| Masks | emd_48547_msk_1.map | 125 MB | Mask map | |
| Filedesc metadata | emd-48547.cif.gz | 3.7 KB | ||
| Others | emd_48547_half_map_1.map.gz emd_48547_half_map_2.map.gz | 115.9 MB 115.9 MB | ||
| Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-48547 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-48547 | HTTPS FTP |
-Validation report
| Summary document | emd_48547_validation.pdf.gz | 1.2 MB | Display | EMDB validaton report |
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| Full document | emd_48547_full_validation.pdf.gz | 1.2 MB | Display | |
| Data in XML | emd_48547_validation.xml.gz | 19.1 KB | Display | |
| Data in CIF | emd_48547_validation.cif.gz | 24.4 KB | Display | |
| Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-48547 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-48547 | HTTPS FTP |
-Related structure data
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Links
| EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Map
| File | Download / File: emd_48547.map.gz / Format: CCP4 / Size: 125 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: 0.77 Å | ||||||||||||||||||||||||||||||||||||
| Density |
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| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
| Details | EMDB XML:
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-Supplemental data
-Mask #1
| File | emd_48547_msk_1.map | ||||||||||||
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-Half map: #1
| File | emd_48547_half_map_1.map | ||||||||||||
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-Half map: #2
| File | emd_48547_half_map_2.map | ||||||||||||
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Sample components
-Entire : gamma-H2AX containing nucleosome bound to MDC1 BRCT
| Entire | Name: gamma-H2AX containing nucleosome bound to MDC1 BRCT |
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| Components |
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-Supramolecule #1: gamma-H2AX containing nucleosome bound to MDC1 BRCT
| Supramolecule | Name: gamma-H2AX containing nucleosome bound to MDC1 BRCT / type: complex / ID: 1 / Parent: 0 |
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| Source (natural) | Organism: Homo sapiens (human) |
-Experimental details
-Structure determination
| Method | cryo EM |
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Processing | single particle reconstruction |
| Aggregation state | particle |
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Sample preparation
| Buffer | pH: 7.5 |
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| Vitrification | Cryogen name: ETHANE |
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Electron microscopy
| Microscope | TFS KRIOS |
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| Image recording | Film or detector model: FEI FALCON III (4k x 4k) / Average electron dose: 50.0 e/Å2 |
| Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
| Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 3.0 µm / Nominal defocus min: 1.0 µm |
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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About Yorodumi




Keywords
Homo sapiens (human)
Authors
Canada, 1 items
Citation


















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Processing
FIELD EMISSION GUN

