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Open data
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Basic information
| Entry | Database: PDB / ID: 30mn | |||||||||
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| Title | PLD-fold vaccinia virus endonuclease K4 with DNA | |||||||||
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Keywords | VIRAL PROTEIN / Nuclease / PLD / Phospholipase D / vaccinia virus / poxvirus / DNase / ssDNA | |||||||||
| Function / homology | Function and homology information | |||||||||
| Biological species | Orthopoxvirus vacciniasynthetic construct (others) | |||||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.6 Å | |||||||||
Authors | Groger, H. / Burmeister, W.P. / Tarbouriech, N. | |||||||||
| Funding support | France, 1items
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Citation | Journal: J Mol Biol / Year: 2026Title: High-resolution Structure of the Vaccinia Virus Phospholipase D-fold Endonuclease K4. Authors: Henri Gröger / Candice Trouba / Jade Barbaste / Guillaume Lacroix / Guy Schoehn / Wim P Burmeister / Nicolas Tarbouriech / ![]() Abstract: Vaccinia virus (VACV) is an orthopoxvirus closely related to mpox virus, which started global outbreaks in 2022. Poxvirus genomes are flanked by short, inverted complementary hairpin telomeres that ...Vaccinia virus (VACV) is an orthopoxvirus closely related to mpox virus, which started global outbreaks in 2022. Poxvirus genomes are flanked by short, inverted complementary hairpin telomeres that feature mismatched bases and insertions essential for viral replication. In this context, a role of the late protein K4 has been proposed. K4 is present in the virion, is apparently non-essential and has a phospholipase D (PLD)-fold as has VACV F13 protein. It also shares fold and nuclease activity with its closest homologue, mammalian PLD3. We established an endonuclease activity against ssDNA and hairpin loops and bubbles in a dsDNA context while RNA is resistant to cleavage. The 2.4 Å cryo-EM structure of K4 shows an unusual octameric assembly, also present in solution. At low concentration, tetramers and dimers similar to the one of hPLD3 are also present. Despite its nuclease activity, in K4 a C-terminal extension blocks the DNA binding pockets. Using an inactive mutant, fortuitously, a DNA 19mer bound simultaneously to 2 sites of the octamer where it displaced the C-termini. DNA binding uses similar residues as the hPLD3 5'-exonuclease, despite different activities and orientations of the DNA. The role of K4 and the control of its activity by the observed auto-inhibition remain enigmatic. | |||||||||
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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 | 30mn.cif.gz | 414.5 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb30mn.ent.gz | 269.5 KB | Display | PDB format |
| PDBx/mmJSON format | 30mn.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/0m/30mn ftp://data.pdbj.org/pub/pdb/validation_reports/0m/30mn | HTTPS FTP |
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-Related structure data
| Related structure data | ![]() 57884MC ![]() 30ieC C: citing same article ( M: map data used to model this data |
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| Similar structure data | Similarity search - Function & homology F&H Search |
| Experimental dataset #1 | Data reference: 10.15151/ESRF-ES-2015807706 / Data set type: raw EM image data |
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Links
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Assembly
| Deposited unit | ![]()
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| 1 | ![]()
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Components
| #1: Protein | Mass: 52079.234 Da / Num. of mol.: 4 / Mutation: H115Q, H325Q Source method: isolated from a genetically manipulated source Source: (gene. exp.) Orthopoxvirus vaccinia / Strain: Copenhagen / Gene: OPG042, K4L / Production host: Trichoplusia ni (cabbage looper) / References: UniProt: P20537#2: DNA chain | Mass: 6005.881 Da / Num. of mol.: 2 / Source method: obtained synthetically / Source: (synth.) synthetic construct (others) Has protein modification | Y | |
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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: Octameric complex of K4 containing mutated histidines in the HKD motif, with DNA bound in chains A and D Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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| Molecular weight | Value: 0.392610 MDa / Experimental value: YES |
| Source (natural) | Organism: Vaccinia virus Copenhagen |
| Source (recombinant) | Organism: Trichoplusia ni (cabbage looper) |
| Details of virus | Type: VIRION |
| Buffer solution | pH: 8.5 / Details: 20 mM Tris-HCl (pH 8.5), 100 mM NaCl, 2 mM DTT |
| Specimen | Conc.: 1 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
| Specimen support | Details: EMS instruments / Grid material: GOLD / Grid mesh size: 300 divisions/in. / Grid type: UltrAuFoil R1.2/1.3 |
| Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 293 K |
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Electron microscopy imaging
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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| Microscopy | Model: TFS KRIOS |
| Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 105000 X / Nominal defocus max: 2400 nm / Nominal defocus min: 700 nm / Cs: 2.7 mm |
| Specimen holder | Cryogen: NITROGEN |
| Image recording | Electron dose: 42 e/Å2 / Detector mode: COUNTING / Film or detector model: GATAN K3 (6k x 4k) / Num. of grids imaged: 1 / Num. of real images: 6075 |
| EM imaging optics | Energyfilter name: GIF Quantum LS / Energyfilter slit width: 20 eV |
| Image scans | Movie frames/image: 40 |
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Processing
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| CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||||||||||
| Symmetry | Point symmetry: C1 (asymmetric) | ||||||||||||||||||||||||||||||||||||||||||||
| 3D reconstruction | Resolution: 2.6 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 23730 / Symmetry type: POINT | ||||||||||||||||||||||||||||||||||||||||||||
| Atomic model building | B value: 133.56 / Protocol: FLEXIBLE FIT / Space: REAL / Target criteria: cross-correlation coefficient | ||||||||||||||||||||||||||||||||||||||||||||
| Atomic model building | PDB-ID: 30IE Accession code: 30IE / Source name: PDB / Type: experimental model | ||||||||||||||||||||||||||||||||||||||||||||
| Refinement | Cross valid method: NONE Stereochemistry target values: GeoStd + Monomer Library + CDL v1.2 | ||||||||||||||||||||||||||||||||||||||||||||
| Displacement parameters | Biso mean: 117.34 Å2 | ||||||||||||||||||||||||||||||||||||||||||||
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About Yorodumi




Orthopoxvirus vaccinia
France, 1items
Citation


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Trichoplusia ni (cabbage looper)
FIELD EMISSION GUN