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- PDB-8amd: Cryo-EM structure of the RecA presynaptic filament from S.pneumoniae -
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Open data
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Basic information
Entry | Database: PDB / ID: 8amd | ||||||
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Title | Cryo-EM structure of the RecA presynaptic filament from S.pneumoniae | ||||||
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![]() | RECOMBINATION / Helical reconstruction / Recombinase / Streptococcus pneumoniae / single-stranded DNA | ||||||
Function / homology | ![]() establishment of competence for transformation / ATP-dependent DNA damage sensor activity / SOS response / single-stranded DNA binding / DNA recombination / damaged DNA binding / DNA repair / ATP hydrolysis activity / ATP binding / cytosol Similarity search - Function | ||||||
Biological species | ![]() ![]() ![]() | ||||||
Method | ELECTRON MICROSCOPY / helical reconstruction / cryo EM / Resolution: 3.9 Å | ||||||
![]() | Perry, T.N. / Fronzes, R. / Polard, P. / Hertzog, M. | ||||||
Funding support | European Union, 1items
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![]() | ![]() Title: Assembly mechanism and cryoEM structure of RecA recombination nucleofilaments from Streptococcus pneumoniae. Authors: Maud Hertzog / Thomas Noé Perry / Pauline Dupaigne / Sandra Serres / Violette Morales / Anne-Lise Soulet / Jason C Bell / Emmanuel Margeat / Stephen C Kowalczykowski / Eric Le Cam / Rémi ...Authors: Maud Hertzog / Thomas Noé Perry / Pauline Dupaigne / Sandra Serres / Violette Morales / Anne-Lise Soulet / Jason C Bell / Emmanuel Margeat / Stephen C Kowalczykowski / Eric Le Cam / Rémi Fronzes / Patrice Polard / ![]() ![]() Abstract: RecA-mediated homologous recombination (HR) is a key mechanism for genome maintenance and plasticity in bacteria. It proceeds through RecA assembly into a dynamic filament on ssDNA, the presynaptic ...RecA-mediated homologous recombination (HR) is a key mechanism for genome maintenance and plasticity in bacteria. It proceeds through RecA assembly into a dynamic filament on ssDNA, the presynaptic filament, which mediates DNA homology search and ordered DNA strand exchange. Here, we combined structural, single molecule and biochemical approaches to characterize the ATP-dependent assembly mechanism of the presynaptic filament of RecA from Streptococcus pneumoniae (SpRecA), in comparison to the Escherichia coli RecA (EcRecA) paradigm. EcRecA polymerization on ssDNA is assisted by the Single-Stranded DNA Binding (SSB) protein, which unwinds ssDNA secondary structures that block EcRecA nucleofilament growth. We report by direct microscopic analysis of SpRecA filamentation on ssDNA that neither of the two paralogous pneumococcal SSBs could assist the extension of SpRecA nucleopolymers. Instead, we found that the conserved RadA helicase promotes SpRecA nucleofilamentation in an ATP-dependent manner. This allowed us to solve the atomic structure of such a long native SpRecA nucleopolymer by cryoEM stabilized with ATPγS. It was found to be equivalent to the crystal structure of the EcRecA filament with a marked difference in how RecA mediates nucleotide orientation in the stretched ssDNA. Then, our results show that SpRecA and EcRecA HR activities are different, in correlation with their distinct ATP-dependent ssDNA binding modes. | ||||||
History |
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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PDBx/mmCIF format | ![]() | 238.5 KB | Display | ![]() |
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PDB format | ![]() | 191.1 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Summary document | ![]() | 1.3 MB | Display | ![]() |
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Full document | ![]() | 1.3 MB | Display | |
Data in XML | ![]() | 47.3 KB | Display | |
Data in CIF | ![]() | 70.4 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 15524MC ![]() 8amfC M: map data used to model this data C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 42007.703 Da / Num. of mol.: 4 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() #2: DNA chain | | Mass: 3605.356 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() #3: Chemical | ChemComp-AGS / Has ligand of interest | Y | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: FILAMENT / 3D reconstruction method: helical reconstruction |
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Sample preparation
Component | Name: Presynaptic filament from S.pneumoniae / Type: COMPLEX / Details: RecA protein forms a dynamic filament on ssDNA / Entity ID: #1-#2 / Source: RECOMBINANT |
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Source (natural) | Organism: ![]() ![]() |
Source (recombinant) | Organism: ![]() ![]() |
Buffer solution | pH: 7.5 |
Specimen | Conc.: 0.2 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Specimen support | Grid material: COPPER / Grid type: EMS Lacey Carbon |
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Talos Arctica / Image courtesy: FEI Company |
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Microscopy | Model: FEI TALOS ARCTICA |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 190000 X / Nominal defocus max: 2500 nm / Nominal defocus min: 800 nm / Cs: 2.7 mm / Alignment procedure: COMA FREE |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Electron dose: 36 e/Å2 / Detector mode: COUNTING / Film or detector model: FEI FALCON III (4k x 4k) / Num. of grids imaged: 1 / Num. of real images: 2896 |
Image scans | Movie frames/image: 40 |
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Processing
Software | Name: PHENIX / Version: 1.14_3260: / Classification: refinement | ||||||||||||||||||||||||
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EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
Helical symmerty | Angular rotation/subunit: 58.46 ° / Axial rise/subunit: 15.38 Å / Axial symmetry: C1 | ||||||||||||||||||||||||
Particle selection | Num. of particles selected: 363828 | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.9 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 188475 / Symmetry type: HELICAL | ||||||||||||||||||||||||
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