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Open data
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Basic information
| Entry | Database: PDB / ID: 7ypo | ||||||
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| Title | Cryo-EM structure of baculovirus LEF-3 in complex with ssDNA | ||||||
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Keywords | DNA BINDING PROTEIN / ssDNA / SSB / Baculovirus | ||||||
| Function / homology | Nucleopolyhedrovirus late expression factor 3 / Nucleopolyhedrovirus late expression factor 3 (LEF-3) / regulation of DNA-templated transcription / DNA binding / DNA / DNA (> 10) / Lef3 Function and homology information | ||||||
| Biological species | Helicoverpa armigera nucleopolyhedrovirussynthetic construct (others) | ||||||
| Method | ELECTRON MICROSCOPY / helical reconstruction / cryo EM / Resolution: 3.5 Å | ||||||
Authors | Yin, J. / Fu, Y. / Rao, G. / Li, Z. / Cao, S. | ||||||
| Funding support | China, 1items
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Citation | Journal: Nucleic Acids Res / Year: 2022Title: Structural transitions during the cooperative assembly of baculovirus single-stranded DNA-binding protein on ssDNA. Authors: Jiayi Yin / Yan Fu / Guibo Rao / Zhiqiang Li / Kexing Tian / Tingting Chong / Kai Kuang / Manli Wang / Zhihong Hu / Sheng Cao / ![]() Abstract: Single-stranded DNA-binding proteins (SSBs) interact with single-stranded DNA (ssDNA) to form filamentous structures with various degrees of cooperativity, as a result of intermolecular interactions ...Single-stranded DNA-binding proteins (SSBs) interact with single-stranded DNA (ssDNA) to form filamentous structures with various degrees of cooperativity, as a result of intermolecular interactions between neighboring SSB subunits on ssDNA. However, it is still challenging to perform structural studies on SSB-ssDNA filaments at high resolution using the most studied SSB models, largely due to the intrinsic flexibility of these nucleoprotein complexes. In this study, HaLEF-3, an SSB protein from Helicoverpa armigera nucleopolyhedrovirus, was used for in vitro assembly of SSB-ssDNA filaments, which were structurally studied at atomic resolution using cryo-electron microscopy. Combined with the crystal structure of ssDNA-free HaLEF-3 octamers, our results revealed that the three-dimensional rearrangement of HaLEF-3 induced by an internal hinge-bending movement is essential for the formation of helical SSB-ssDNA complexes, while the contacting interface between adjacent HaLEF-3 subunits remains basically intact. We proposed a local cooperative SSB-ssDNA binding model, in which, triggered by exposure to oligonucleotides, HaLEF-3 molecules undergo ring-to-helix transition to initiate continuous SSB-SSB interactions along ssDNA. Unique structural features revealed by the assembly of HaLEF-3 on ssDNA suggest that HaLEF-3 may represent a new class of SSB. | ||||||
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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 | 7ypo.cif.gz | 257.3 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb7ypo.ent.gz | 204.8 KB | Display | PDB format |
| PDBx/mmJSON format | 7ypo.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/yp/7ypo ftp://data.pdbj.org/pub/pdb/validation_reports/yp/7ypo | HTTPS FTP |
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-Related structure data
| Related structure data | ![]() 34010MC ![]() 7ynyC ![]() 7ypqC 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 |
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Links
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Assembly
| Deposited unit | ![]()
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| Noncrystallographic symmetry (NCS) | NCS domain:
NCS domain segments:
NCS oper:
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Components
| #1: Protein | Mass: 47637.707 Da / Num. of mol.: 4 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Helicoverpa armigera nucleopolyhedrovirusProduction host: ![]() #2: DNA chain | | Mass: 8724.834 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) synthetic construct (others) |
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-Experimental details
-Experiment
| Experiment | Method: ELECTRON MICROSCOPY |
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| EM experiment | Aggregation state: HELICAL ARRAY / 3D reconstruction method: helical reconstruction |
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Sample preparation
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| Source (natural) | Organism: Helicoverpa armigera nucleopolyhedrovirus | ||||||||||||||||||||||||
| Source (recombinant) | Organism: ![]() | ||||||||||||||||||||||||
| Buffer solution | pH: 6.3 | ||||||||||||||||||||||||
| Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | ||||||||||||||||||||||||
| Vitrification | Cryogen name: ETHANE |
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Electron microscopy imaging
| Microscopy | Model: JEOL CRYO ARM 300 |
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| Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2500 nm / Nominal defocus min: 500 nm |
| Image recording | Electron dose: 40 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
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Processing
| Software | Name: PHENIX / Version: 1.18.2_3874: / Classification: refinement | ||||||||||||||||||||||||
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| CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
| Helical symmerty | Angular rotation/subunit: -108.281 ° / Axial rise/subunit: 15.105 Å / Axial symmetry: C1 | ||||||||||||||||||||||||
| 3D reconstruction | Resolution: 3.5 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 530580 / Symmetry type: HELICAL | ||||||||||||||||||||||||
| Refinement | Cross valid method: NONE Stereochemistry target values: GeoStd + Monomer Library + CDL v1.2 | ||||||||||||||||||||||||
| Displacement parameters | Biso mean: 51.02 Å2 | ||||||||||||||||||||||||
| Refine LS restraints |
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| Refine LS restraints NCS |
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About Yorodumi




Helicoverpa armigera nucleopolyhedrovirus
China, 1items
Citation



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FIELD EMISSION GUN