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Open data
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Basic information
| Entry | Database: PDB / ID: 8sfh | ||||||
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| Title | WT CRISPR-Cas12a with a 5bp R-loop | ||||||
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Keywords | DNA BINDING PROTEIN/DNA/RNA / CRISPR / R-loop / endonuclease / DNA BINDING PROTEIN / DNA BINDING PROTEIN-DNA-RNA complex | ||||||
| Function / homology | Function and homology informationBacillus subtilis ribonuclease / deoxyribonuclease I / deoxyribonuclease I activity / defense response to virus / lyase activity / DNA binding / RNA binding Similarity search - Function | ||||||
| Biological species | Acidaminococcus sp. BV3L6 (bacteria)synthetic construct (others) | ||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.4 Å | ||||||
Authors | Strohkendl, I. / Taylor, D.W. | ||||||
| Funding support | United States, 1items
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Citation | Journal: Mol Cell / Year: 2024Title: Cas12a domain flexibility guides R-loop formation and forces RuvC resetting. Authors: Isabel Strohkendl / Aakash Saha / Catherine Moy / Alexander-Hoi Nguyen / Mohd Ahsan / Rick Russell / Giulia Palermo / David W Taylor / ![]() Abstract: The specific nature of CRISPR-Cas12a makes it a desirable RNA-guided endonuclease for biotechnology and therapeutic applications. To understand how R-loop formation within the compact Cas12a enables ...The specific nature of CRISPR-Cas12a makes it a desirable RNA-guided endonuclease for biotechnology and therapeutic applications. To understand how R-loop formation within the compact Cas12a enables target recognition and nuclease activation, we used cryo-electron microscopy to capture wild-type Acidaminococcus sp. Cas12a R-loop intermediates and DNA delivery into the RuvC active site. Stages of Cas12a R-loop formation-starting from a 5-bp seed-are marked by distinct REC domain arrangements. Dramatic domain flexibility limits contacts until nearly complete R-loop formation, when the non-target strand is pulled across the RuvC nuclease and coordinated domain docking promotes efficient cleavage. Next, substantial domain movements enable target strand repositioning into the RuvC active site. Between cleavage events, the RuvC lid conformationally resets to occlude the active site, requiring re-activation. These snapshots build a structural model depicting Cas12a DNA targeting that rationalizes observed specificity and highlights mechanistic comparisons to other class 2 effectors. | ||||||
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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 | 8sfh.cif.gz | 288.1 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb8sfh.ent.gz | 222.7 KB | Display | PDB format |
| PDBx/mmJSON format | 8sfh.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Summary document | 8sfh_validation.pdf.gz | 1.2 MB | Display | wwPDB validaton report |
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| Full document | 8sfh_full_validation.pdf.gz | 1.2 MB | Display | |
| Data in XML | 8sfh_validation.xml.gz | 47 KB | Display | |
| Data in CIF | 8sfh_validation.cif.gz | 69.7 KB | Display | |
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/sf/8sfh ftp://data.pdbj.org/pub/pdb/validation_reports/sf/8sfh | HTTPS FTP |
-Related structure data
| Related structure data | ![]() 40441MC ![]() 8sfiC ![]() 8sfjC ![]() 8sflC ![]() 8sfnC ![]() 8sfoC ![]() 8sfpC ![]() 8sfqC ![]() 8sfrC 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: 151418.953 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Acidaminococcus sp. BV3L6 (bacteria) / Gene: cas12a, cpf1, HMPREF1246_0236 / Production host: ![]() References: UniProt: U2UMQ6, deoxyribonuclease I, Bacillus subtilis ribonuclease |
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| #2: RNA chain | Mass: 8598.088 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) synthetic construct (others) |
| #3: DNA chain | Mass: 9882.405 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) synthetic construct (others) |
| #4: DNA chain | Mass: 9797.312 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) synthetic construct (others) |
| Has protein modification | N |
-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: WT AsCas12a incubated with 8bp-complementary target DNA. Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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| Source (natural) | Organism: Acidaminococcus sp. BV3L6 (bacteria) |
| Source (recombinant) | Organism: ![]() |
| Buffer solution | pH: 7 |
| Specimen | Conc.: 1 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
| 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: 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 defocus max: 2500 nm / Nominal defocus min: 1500 nm |
| Image recording | Electron dose: 80 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
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Processing
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| CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
| 3D reconstruction | Resolution: 3.4 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 60595 / Symmetry type: POINT | ||||||||||||||||||||||||
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About Yorodumi




Acidaminococcus sp. BV3L6 (bacteria)
United States, 1items
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FIELD EMISSION GUN