+Open data
-Basic information
Entry | Database: PDB / ID: 7xfl | ||||||
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Title | Structure of nucleosome-AAG complex (A-53I, free state) | ||||||
Components |
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Keywords | DNA BINDING PROTEIN/DNA / Nucleosome / AAG / Cryo-EM / DNA repair / Base excision repair / DNA BINDING PROTEIN / DNA BINDING PROTEIN-DNA complex | ||||||
Function / homology | Function and homology information structural constituent of chromatin / nucleosome / nucleosome assembly / protein heterodimerization activity / DNA binding / nucleoplasm / nucleus Similarity search - Function | ||||||
Biological species | Xenopus laevis (African clawed frog) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / negative staining / cryo EM / Resolution: 2.8 Å | ||||||
Authors | Zheng, L. / Tsai, B. / Gao, N. | ||||||
Funding support | China, 1items
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Citation | Journal: Cell Discov / Year: 2023 Title: Structural and mechanistic insights into the DNA glycosylase AAG-mediated base excision in nucleosome. Authors: Lvqin Zheng / Bin Tsai / Ning Gao / Abstract: The engagement of a DNA glycosylase with a damaged DNA base marks the initiation of base excision repair. Nucleosome-based packaging of eukaryotic genome obstructs DNA accessibility, and how DNA ...The engagement of a DNA glycosylase with a damaged DNA base marks the initiation of base excision repair. Nucleosome-based packaging of eukaryotic genome obstructs DNA accessibility, and how DNA glycosylases locate the substrate site on nucleosomes is currently unclear. Here, we report cryo-electron microscopy structures of nucleosomes bearing a deoxyinosine (DI) in various geometric positions and structures of them in complex with the DNA glycosylase AAG. The apo nucleosome structures show that the presence of a DI alone perturbs nucleosomal DNA globally, leading to a general weakening of the interface between DNA and the histone core and greater flexibility for the exit/entry of the nucleosomal DNA. AAG makes use of this nucleosomal plasticity and imposes further local deformation of the DNA through formation of the stable enzyme-substrate complex. Mechanistically, local distortion augmentation, translation/rotational register shift and partial opening of the nucleosome are employed by AAG to cope with substrate sites in fully exposed, occluded and completely buried positions, respectively. Our findings reveal the molecular basis for the DI-induced modification on the structural dynamics of the nucleosome and elucidate how the DNA glycosylase AAG accesses damaged sites on the nucleosome with different solution accessibility. | ||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 7xfl.cif.gz | 271.9 KB | Display | PDBx/mmCIF format |
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PDB format | pdb7xfl.ent.gz | 200.7 KB | Display | PDB format |
PDBx/mmJSON format | 7xfl.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 7xfl_validation.pdf.gz | 1.1 MB | Display | wwPDB validaton report |
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Full document | 7xfl_full_validation.pdf.gz | 1.1 MB | Display | |
Data in XML | 7xfl_validation.xml.gz | 32.1 KB | Display | |
Data in CIF | 7xfl_validation.cif.gz | 49.4 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/xf/7xfl ftp://data.pdbj.org/pub/pdb/validation_reports/xf/7xfl | HTTPS FTP |
-Related structure data
Related structure data | 33175MC 7xfcC 7xfhC 7xfiC 7xfjC 7xfmC 7xfnC 7xnpC M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
-Protein , 4 types, 8 molecules AEBFCGDH
#1: Protein | Mass: 15421.101 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Xenopus laevis (African clawed frog) / Production host: Escherichia coli (E. coli) / References: UniProt: P84233 #2: Protein | Mass: 11394.426 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Xenopus laevis (African clawed frog) / Production host: Escherichia coli (E. coli) / References: UniProt: P62799 #3: Protein | Mass: 14093.436 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Xenopus laevis (African clawed frog) / Production host: Escherichia coli (E. coli) / References: UniProt: P06897 #4: Protein | Mass: 13965.265 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Xenopus laevis (African clawed frog) / Production host: Escherichia coli (E. coli) / References: UniProt: P02281 |
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-DNA chain , 2 types, 2 molecules IJ
#5: DNA chain | Mass: 47170.023 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Xenopus laevis (African clawed frog) / Production host: Escherichia coli (E. coli) |
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#6: DNA chain | Mass: 46655.711 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Xenopus laevis (African clawed frog) / Production host: Escherichia coli (E. coli) |
-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: CELL / 3D reconstruction method: single particle reconstruction |
-Sample preparation
Component | Name: complex / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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Source (natural) | Organism: Xenopus laevis (African clawed frog) |
Source (recombinant) | Organism: Escherichia coli (E. coli) |
Buffer solution | pH: 7.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: YES / Vitrification applied: YES |
EM staining | Type: NEGATIVE / Material: Uranyl acetate |
Vitrification | Cryogen name: NITROGEN |
-Electron microscopy imaging
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: SPOT SCAN |
Electron lens | Mode: DARK FIELD / Nominal defocus max: 1700 nm / Nominal defocus min: 1200 nm |
Image recording | Electron dose: 64 e/Å2 / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
-Processing
Software | Name: PHENIX / Version: 1.19.2_4158: / Classification: refinement | ||||||||||||||||||||||||
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
3D reconstruction | Resolution: 2.8 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 129507 / Symmetry type: POINT | ||||||||||||||||||||||||
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