9E91

Ec83 Retron PtuA Dimer bound to ATP

9E91 の概要

• エントリーDOI: 10.2210/pdb9e91/pdb
• EMDBエントリー: 47739
• 分子名称: Retron Ec83 probable ATPase, ADENOSINE-5'-TRIPHOSPHATE (2 entities in total)
• 機能のキーワード: atpase, retron, antiviral protein, dimer
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 124550.17

構造登録者

Rish, A.D.,Wang, C.,Fu, T.M. (登録日: 2024-11-06, 公開日: 2025-07-02, 最終更新日: 2025-12-10)

主引用文献

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

PubMed Abstract: Retrons are antiphage defense systems that produce multicopy single-stranded DNA (msDNA) and hold promise for genome engineering. However, the mechanisms of defense remain unclear. The Retron-Septu system integrates retron and Septu antiphage defenses. Cryo-electron microscopy structures reveal asymmetric nucleoprotein complexes comprising a reverse transcriptase, 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: 40504952
DOI: 10.1126/science.adv3344

実験手法

ELECTRON MICROSCOPY (3.31 Å)