+Open data
-Basic information
Entry | Database: PDB / ID: 8fd2 | ||||||
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Title | Cryo-EM structure of Cascade complex in type I-B CAST system | ||||||
Components |
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Keywords | DNA BINDING PROTEIN / Cascade / I-B / CAST | ||||||
Function / homology | Function and homology information | ||||||
Biological species | Nostoc sp. 'Peltigera membranacea cyanobiont' 210A (bacteria) synthetic construct (others) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.65 Å | ||||||
Authors | Chang, L. / Wang, S. | ||||||
Funding support | United States, 1items
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Citation | Journal: Cell / Year: 2023 Title: Molecular mechanism for Tn7-like transposon recruitment by a type I-B CRISPR effector. Authors: Shukun Wang / Clinton Gabel / Romana Siddique / Thomas Klose / Leifu Chang / Abstract: Tn7-like transposons have co-opted CRISPR-Cas systems to facilitate the movement of their own DNA. These CRISPR-associated transposons (CASTs) are promising tools for programmable gene knockin. A key ...Tn7-like transposons have co-opted CRISPR-Cas systems to facilitate the movement of their own DNA. These CRISPR-associated transposons (CASTs) are promising tools for programmable gene knockin. A key feature of CASTs is their ability to recruit Tn7-like transposons to nuclease-deficient CRISPR effectors. However, how Tn7-like transposons are recruited by diverse CRISPR effectors remains poorly understood. Here, we present the cryo-EM structure of a recruitment complex comprising the Cascade complex, TniQ, TnsC, and the target DNA in the type I-B CAST from Peltigera membranacea cyanobiont 210A. Target DNA recognition by Cascade induces conformational changes in Cas6 and primes TniQ recruitment through its C-terminal domain. The N-terminal domain of TniQ is bound to the seam region of the TnsC spiral heptamer. Our findings provide insights into the diverse mechanisms for the recruitment of Tn7-like transposons to CRISPR effectors and will aid in the development of CASTs as gene knockin tools. | ||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8fd2.cif.gz | 568.5 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8fd2.ent.gz | 465.1 KB | Display | PDB format |
PDBx/mmJSON format | 8fd2.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8fd2_validation.pdf.gz | 1.1 MB | Display | wwPDB validaton report |
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Full document | 8fd2_full_validation.pdf.gz | 1.1 MB | Display | |
Data in XML | 8fd2_validation.xml.gz | 89.7 KB | Display | |
Data in CIF | 8fd2_validation.cif.gz | 135.2 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/fd/8fd2 ftp://data.pdbj.org/pub/pdb/validation_reports/fd/8fd2 | HTTPS FTP |
-Related structure data
Related structure data | 29000MC 8fcjC 8fcuC 8fcvC 8fcwC 8fcxC 8fd3C 8ff4C 8ff5C M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
-Type I-B CRISPR-associated protein ... , 4 types, 11 molecules BCDEFGHIJKL
#2: Protein | Mass: 24945.744 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Nostoc sp. 'Peltigera membranacea cyanobiont' 210A (bacteria) Gene: cas6 / Production host: Escherichia coli (E. coli) / References: UniProt: A0A235IH92 | ||||
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#3: Protein | Mass: 37298.996 Da / Num. of mol.: 6 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Nostoc sp. 'Peltigera membranacea cyanobiont' 210A (bacteria) Gene: CDG76_09080 / Production host: Escherichia coli (E. coli) / References: UniProt: A0A235IG15 #4: Protein | | Mass: 63474.328 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Nostoc sp. 'Peltigera membranacea cyanobiont' 210A (bacteria) Gene: CDG76_09085 / Production host: Escherichia coli (E. coli) / References: UniProt: A0A235IGR9 #5: Protein | Mass: 16314.365 Da / Num. of mol.: 3 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Nostoc sp. 'Peltigera membranacea cyanobiont' 210A (bacteria) Gene: CDG76_09085 / Production host: Escherichia coli (E. coli) / References: UniProt: A0A235IGR9 |
-Protein / RNA chain , 2 types, 2 molecules AM
#1: Protein | Mass: 24852.906 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Nostoc sp. 'Peltigera membranacea cyanobiont' 210A (bacteria) Gene: cas5 / Production host: Escherichia coli (E. coli) / References: UniProt: A0A235IG00 |
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#6: RNA chain | Mass: 22876.527 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) synthetic construct (others) |
-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
-Sample preparation
Component | Name: Cascade complex in type I-B CAST system / Type: COMPLEX / Entity ID: all / Source: MULTIPLE SOURCES | ||||||||||||
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Source (natural) |
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Source (recombinant) | Organism: Escherichia coli (E. coli) | ||||||||||||
Buffer solution | pH: 7.5 | ||||||||||||
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | ||||||||||||
Vitrification | Cryogen name: ETHANE |
-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: 54 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) |
-Processing
Software | Name: PHENIX / Version: 1.20.1_4487: / Classification: refinement | ||||||||||||||||||||||||
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CTF correction | Type: PHASE FLIPPING ONLY | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.65 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 139953 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
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