9E90
Ec83 Retron PtuA/PtuB (2-1) complex bound to ATP
Summary for 9E90
| Entry DOI | 10.2210/pdb9e90/pdb |
| EMDB information | 47738 |
| Descriptor | Retron Ec83 putative HNH endonuclease, Retron Ec83 probable ATPase, ZINC ION, ... (4 entities in total) |
| Functional Keywords | atpase, retron, antiviral protein, dimer |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 3 |
| Total formula weight | 154848.90 |
| Authors | Rish, A.D.,Wang, C.,Fu, T.M. (deposition date: 2024-11-06, release date: 2025-07-02, Last modification date: 2025-09-03) |
| Primary citation | Wang, C.,Rish, A.D.,Armbruster, E.G.,Xie, J.,Loveland, A.B.,Shen, Z.,Gu, B.,Korostelev, A.A.,Pogliano, J.,Fu, T.M. Disassembly activates Retron-Septu for antiphage defense. Science, 389:eadv3344-eadv3344, 2025 Cited by PubMed Abstract: Retrons are antiphage defense systems that produce multicopy single-stranded DNA (msDNA) and hold promises for genome engineering. However, the mechanisms of defense remain unclear. The Retron-Septu system uniquely integrates retron and Septu antiphage defenses. Cryo-electron microscopy structures reveal asymmetric nucleoprotein complexes comprising a reverse transcriptase (RT), msDNA (a hybrid of msdDNA and msrRNA), and two PtuAB copies. msdDNA and msrRNA are essential for assembling this complex, with msrRNA adopting a conserved lariat-like structure that regulates reverse transcription. Notably, the assembled Retron-Septu complex is inactive, with msdDNA occupying the PtuA DNA-binding site. Activation occurs upon disassembly, releasing PtuAB, which degrades single-stranded DNA to restrict phage replication. This "arrest-and-release" mechanism underscores the dynamic regulatory roles of msDNA, advancing our understanding of antiphage defense strategies. PubMed: 40504952DOI: 10.1126/science.adv3344 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.45 Å) |
Structure validation
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