24NC

DRT4 homohexamer with dGTP, RNA

24NC の概要

• エントリーDOI: 10.2210/pdb24nc/pdb
• EMDBエントリー: 69683
• 分子名称: Reverse transcriptase domain-containing protein, 2'-DEOXYGUANOSINE-5'-TRIPHOSPHATE, MAGNESIUM ION, ... (5 entities in total)
• 機能のキーワード: drt4; reverse transcriptase; terminal transferase; nuclease, immune system
• 由来する生物種: Enterobacteriaceae (enterobacteria)
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 384223.26

構造登録者

Wang, L.,Li, J. (登録日: 2026-03-11, 公開日: 2026-05-27, 最終更新日: 2026-06-10)

主引用文献

Rong, X.,Xiao, J.,Zhao, X.,Yan, Y.,Li, J.,Chen, Y.,Fan, Y.,Liu, Z.,Cao, Y.,Chen, F.,Cheng, R.,Wang, X.,Wang, L.,Zhu, B.
DNA polymerization activates RNA cleavage of a reverse transcriptase-like antiviral enzyme.
Science, :eaef3178-eaef3178, 2026

PubMed Abstract: Defense-associated reverse transcriptases (DRTs) transcribe noncoding RNAs (ncRNAs) for antiviral defense, but the mechanisms of ncRNA-independent DRTs remain unclear. In this work, we show that a single DRT4 mediates RNA-targeting antiphage defense by integrating DNA polymerase, exonuclease, and RNA endonuclease activities. First, through an equilibrium between its DNA polymerase and exonuclease activities, DRT4 senses phage infection, as elevated dNTP levels shift the equilibrium toward polymerase activity, thereby promoting protein-primed single-stranded DNA (ssDNA) synthesis. Second, ssDNA of sufficient length, phage DNA-binding proteins, and deoxyguanosine triphosphate collectively activate an unusual RNA endonuclease activity of DRT4, excising 3'-guanosine monophosphate from both phage and host RNA to terminate infection. These findings reveal a distinctive immune strategy combining nucleic acid synthesis and degradation, expanding the functional landscape of DRTs for new DNA- and RNA-processing technologies.

PubMed: 42166559
DOI: 10.1126/science.aef3178

実験手法

ELECTRON MICROSCOPY (2.22 Å)