9IOA

Cryo-EM structure of the tetrameric DRT9-ncRNA complex

9IOA の概要

• エントリーDOI: 10.2210/pdb9ioa/pdb
• EMDBエントリー: 60724
• 分子名称: RNA (177-MER), RNA-dependent DNA polymerase (2 entities in total)
• 機能のキーワード: rna binding, protein-rna complex, antiviral protein/rna, antiviral protein-rna complex
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 460449.02

構造登録者

Zhang, J.T.,Song, X.Y.,Wei, X.Y.,Jia, N. (登録日: 2024-07-08, 公開日: 2025-05-14, 最終更新日: 2025-07-02)

主引用文献

Song, X.Y.,Xia, Y.,Zhang, J.T.,Liu, Y.J.,Qi, H.,Wei, X.Y.,Hu, H.,Xia, Y.,Liu, X.,Ma, Y.F.,Jia, N.
Bacterial reverse transcriptase synthesizes long poly(A)-rich cDNA for antiphage defense.
Science, 388:eads4639-eads4639, 2025

PubMed Abstract: Prokaryotic defense-associated reverse transcriptases (DRTs) were recently identified with antiviral functions; however, their functional mechanisms remain largely unexplored. Here we show that DRT9 forms a hexameric complex with its upstream noncoding RNA (ncRNA) to mediate antiphage defense by inducing cell growth arrest through abortive infection. Upon phage infection, the phage-encoded ribonucleotide reductase NrdAB complex increases intracellular deoxyadenosine triphosphate levels, activating DRT9 to synthesize long, polyadenylate [poly(A)]-rich single-stranded complementary DNA (cDNA), which likely sequesters the essential phage single-stranded DNA binding (SSB) protein and disrupts phage propagation. We further determined the cryo-electron microscopy structure of the DRT9-ncRNA hexamer complex, providing mechanistic insights into its cDNA synthesis. These findings highlight the diversity of RT-based antiviral defense mechanisms, expand our understanding of RT biological functions, and provide a structural basis for developing DRT9-based biotechnological tools.

PubMed: 40310939
DOI: 10.1126/science.ads4639

実験手法

ELECTRON MICROSCOPY (2.59 Å)