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Open data
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Basic information
| Entry | Database: PDB / ID: 9nlv | |||||||||||||||||||||||||||
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| Title | Cryo-EM structure of hexameric SenDRT9 RT-ncRNA complex | |||||||||||||||||||||||||||
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Keywords | IMMUNE SYSTEM / DRT9 / Polymerase | |||||||||||||||||||||||||||
| Function / homology | : / Reverse transcriptase domain / Reverse transcriptase (RNA-dependent DNA polymerase) / Reverse transcriptase (RT) catalytic domain profile. / DNA/RNA polymerase superfamily / RNA / RNA (> 10) / RNA (> 100) / RNA-dependent DNA polymerase Function and homology information | |||||||||||||||||||||||||||
| Biological species | ![]() Salmonella enterica (bacteria) | |||||||||||||||||||||||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.6 Å | |||||||||||||||||||||||||||
Authors | Burman, N. / Pandey, S. / Wiedenheft, B. / Sternberg, S.H. | |||||||||||||||||||||||||||
| Funding support | United States, 2items
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Citation | Journal: Nature / Year: 2025Title: Protein-primed homopolymer synthesis by an antiviral reverse transcriptase. Authors: Stephen Tang / Rimantė Žedaveinytė / Nathaniel Burman / Shishir Pandey / Josephine L Ramirez / Louie M Kulber / Tanner Wiegand / Royce A Wilkinson / Yanzhe Ma / Dennis J Zhang / George D ...Authors: Stephen Tang / Rimantė Žedaveinytė / Nathaniel Burman / Shishir Pandey / Josephine L Ramirez / Louie M Kulber / Tanner Wiegand / Royce A Wilkinson / Yanzhe Ma / Dennis J Zhang / George D Lampe / Mirela Berisa / Marko Jovanovic / Blake Wiedenheft / Samuel H Sternberg / ![]() Abstract: Bacteria defend themselves from viral predation using diverse immune systems, many of which target foreign DNA for degradation. Defence-associated reverse transcriptase (DRT) systems provide an ...Bacteria defend themselves from viral predation using diverse immune systems, many of which target foreign DNA for degradation. Defence-associated reverse transcriptase (DRT) systems provide an intriguing counterpoint to this strategy by using DNA synthesis instead. We and others recently showed that DRT2 systems use an RNA template to assemble a de novo gene that encodes the antiviral effector protein Neo. It remains unclear whether similar mechanisms of defence are used by other related DRT families. Here, we show that DRT9 systems defend against phage using DNA homopolymer synthesis. Viral infection triggers polydeoxyadenylate (poly-dA) accumulation in the cell, driving abortive infection and population-level immunity. Cryo-electron microscopy structures reveal how a non-coding RNA serves as both a structural scaffold and reverse transcription template to direct hexameric complex assembly and poly-dA synthesis. Notably, biochemical and functional experiments identify tyrosine residues within the reverse transcriptase itself that probably prime DNA synthesis, leading to the formation of protein-DNA covalent adducts. Synthesis of poly-dA by DRT9 in vivo is regulated by the competing activities of phage-encoded triggers and host-encoded silencers. Collectively, our study identifies a nucleic-acid-driven defence system that expands the paradigm of bacterial immunity and broadens the known functions of reverse transcriptases. | |||||||||||||||||||||||||||
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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 | 9nlv.cif.gz | 1010.8 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb9nlv.ent.gz | 822 KB | Display | PDB format |
| PDBx/mmJSON format | 9nlv.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Summary document | 9nlv_validation.pdf.gz | 1.2 MB | Display | wwPDB validaton report |
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| Full document | 9nlv_full_validation.pdf.gz | 1.2 MB | Display | |
| Data in XML | 9nlv_validation.xml.gz | 101.1 KB | Display | |
| Data in CIF | 9nlv_validation.cif.gz | 167.9 KB | Display | |
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/nl/9nlv ftp://data.pdbj.org/pub/pdb/validation_reports/nl/9nlv | HTTPS FTP |
-Related structure data
| Related structure data | ![]() 49523MC ![]() 9nlxC 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: 58318.961 Da / Num. of mol.: 6 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() #2: RNA chain | Mass: 47241.750 Da / Num. of mol.: 6 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Salmonella enterica (bacteria) / Production host: ![]() Has protein modification | N | |
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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: Sen DRT9 hexameric ribonucleoprotein complex / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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| Molecular weight | Experimental value: NO |
| Source (natural) | Organism: Salmonella enterica (bacteria) |
| Source (recombinant) | Organism: ![]() |
| Buffer solution | pH: 8 |
| Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
| Specimen support | Grid material: COPPER / Grid mesh size: 300 divisions/in. / Grid type: Quantifoil R1.2/1.3 |
| Vitrification | Cryogen name: ETHANE |
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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: FIELD EMISSION GUN / Accelerating voltage: 200 kV / Illumination mode: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 45000 X / Nominal defocus max: 2500 nm / Nominal defocus min: 800 nm / Alignment procedure: COMA FREE |
| Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
| Image recording | Electron dose: 59.8 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) / Num. of grids imaged: 1 |
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Processing
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| CTF correction | Details: Patch CTF estimation / Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||
| Particle selection | Num. of particles selected: 6029711 / Details: Blob picking | ||||||||||||||||||||||||||||||||
| Symmetry | Point symmetry: D3 (2x3 fold dihedral) | ||||||||||||||||||||||||||||||||
| 3D reconstruction | Resolution: 2.6 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 500162 / Algorithm: FOURIER SPACE / Num. of class averages: 1 / Symmetry type: POINT | ||||||||||||||||||||||||||||||||
| Atomic model building | B value: 101.4 / Protocol: FLEXIBLE FIT / Space: REAL / Target criteria: Cross-correlation coefficient | ||||||||||||||||||||||||||||||||
| Atomic model building | Details: The initial model for the RT was produced using AlphaFold 3 Source name: AlphaFold / Type: in silico model | ||||||||||||||||||||||||||||||||
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About Yorodumi






United States, 2items
Citation



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FIELD EMISSION GUN