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Open data
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Basic information
| Entry | Database: PDB / ID: 8u5y | ||||||
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| Title | human RADX trimer bound to ssDNA | ||||||
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Keywords | DNA BINDING PROTEIN/DNA / oligomer OB-fold / RAD51 regulator / DNA BINDING PROTEIN / DNA BINDING PROTEIN-DNA complex | ||||||
| Function / homology | Function and homology informationnegative regulation of double-strand break repair via homologous recombination / regulation of DNA repair / replication fork / single-stranded DNA binding / nuclear speck / RNA binding Similarity search - Function | ||||||
| Biological species | Homo sapiens (human) | ||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.01 Å | ||||||
Authors | Balakrishnan, S. / Chazin, W.J. | ||||||
| Funding support | United States, 1items
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Citation | Journal: bioRxiv / Year: 2023Title: Structure of RADX and mechanism for regulation of RAD51 nucleofilaments. Authors: Swati Balakrishnan / Madison Adolph / Miaw-Sheue Tsai / Kaitlyn Gallagher / David Cortez / Walter J Chazin / ![]() Abstract: Replication fork reversal is a fundamental process required for resolution of encounters with DNA damage. A key step in the stabilization and eventual resolution of reversed forks is formation of ...Replication fork reversal is a fundamental process required for resolution of encounters with DNA damage. A key step in the stabilization and eventual resolution of reversed forks is formation of RAD51 nucleoprotein filaments on exposed ssDNA. To avoid genome instability, RAD51 filaments are tightly controlled by a variety of positive and negative regulators. RADX is a recently discovered negative regulator that binds tightly to ssDNA, directly interacts with RAD51, and regulates replication fork reversal and stabilization in a context-dependent manner. Here we present a structure-based investigation of RADX's mechanism of action. Mass photometry experiments showed that RADX forms multiple oligomeric states in a concentration dependent manner, with a predominance of trimers in the presence of ssDNA. The structure of RADX, which has no structurally characterized orthologs, was determined by cryo-electron microscopy (EM) from maps in the 2-3 Å range. The structure reveals the molecular basis for RADX oligomerization and binding of ssDNA binding. The binding of RADX to RAD51 filaments was imaged by negative stain EM, which showed a RADX oligomer at the end of filaments. Based on these results, we propose a model in which RADX functions by capping and restricting the growing end of RAD51 filaments. | ||||||
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Structure visualization
| Structure viewer | Molecule: Molmil Jmol/JSmol |
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Downloads & links
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Download
| PDBx/mmCIF format | 8u5y.cif.gz | 809.5 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb8u5y.ent.gz | Display | PDB format | |
| PDBx/mmJSON format | 8u5y.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/u5/8u5y ftp://data.pdbj.org/pub/pdb/validation_reports/u5/8u5y | HTTPS FTP |
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-Related structure data
| Related structure data | ![]() 41939MC M: map data used to model this data C: citing same article ( |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
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Assembly
| Deposited unit | ![]()
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Components
| #1: Protein | Mass: 97680.094 Da / Num. of mol.: 3 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: RADX / Cell line (production host): Expi293F / Production host: Homo sapiens (human) / References: UniProt: Q6NSI4#2: DNA chain | | Mass: 7559.863 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) Homo sapiens (human) |
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-Experimental details
-Experiment
| Experiment | Method: ELECTRON MICROSCOPY |
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| EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
| Component | Name: RADX trimer bound to ssDNA dT25 / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT | ||||||||||||||||||||||||||||||
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| Molecular weight | Value: 0.45 MDa / Experimental value: NO | ||||||||||||||||||||||||||||||
| Source (natural) | Organism: Homo sapiens (human) | ||||||||||||||||||||||||||||||
| Source (recombinant) | Organism: Homo sapiens (human) | ||||||||||||||||||||||||||||||
| Buffer solution | pH: 7.5 | ||||||||||||||||||||||||||||||
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| Specimen | Conc.: 0.145 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES / Details: Sample was cross-linked using BS3 | ||||||||||||||||||||||||||||||
| Specimen support | Grid material: COPPER / Grid mesh size: 300 divisions/in. / Grid type: Quantifoil R1.2/1.3 | ||||||||||||||||||||||||||||||
| Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: HELIUM / Humidity: 100 % / Chamber temperature: 277.15 K |
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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: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2000 nm / Nominal defocus min: 800 nm |
| Image recording | Electron dose: 48.38 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) / Num. of grids imaged: 1 |
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Processing
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| CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | |||||||||||||||||||||
| Particle selection | Num. of particles selected: 400000 | |||||||||||||||||||||
| 3D reconstruction | Resolution: 3.01 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 143622 / Symmetry type: POINT | |||||||||||||||||||||
| Atomic model building | Protocol: AB INITIO MODEL |
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About Yorodumi




Homo sapiens (human)
United States, 1items
Citation



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FIELD EMISSION GUN