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Publication Abstract from PubMed

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 non-coding RNA (ncRNA) to mediate antiphage defense by inducing cell growth arrest via abortive infection. Upon phage infection, the phage-encoded ribonucleotide reductase NrdAB complex elevates intracellular dATP levels, activating DRT9 to synthesize long, poly-A-rich single-stranded cDNA, which likely sequesters the essential phage 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.

Bacterial reverse transcriptase synthesizes long poly-A-rich cDNA for antiphage defense.,Song XY, Xia Y, Zhang JT, Liu YJ, Qi H, Wei XY, Hu H, Xia Y, Liu X, Ma YF, Jia N Science. 2025 May 1:eads4639. doi: 10.1126/science.ads4639. PMID:40310939^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.