8VX9

Structure of HamAB apo complex from the Escherichia coli Hachiman defense system

8VX9 の概要

• エントリーDOI: 10.2210/pdb8vx9/pdb
• EMDBエントリー: 43613
• 分子名称: HamA, HamB (2 entities in total)
• 機能のキーワード: nuclease-helicase complex, antiphage defense system, immune system
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 159822.25

構造登録者

Tuck, O.T.,Doudna, J.A. (登録日: 2024-02-03, 公開日: 2024-03-13, 最終更新日: 2024-03-20)

主引用文献

Tuck, O.T.,Adler, B.A.,Armbruster, E.G.,Lahiri, A.,Hu, J.J.,Zhou, J.,Pogliano, J.,Doudna, J.A.
Hachiman is a genome integrity sensor.
Biorxiv, 2024

PubMed Abstract: Hachiman is a broad-spectrum antiphage defense system of unknown function. We show here that Hachiman comprises a heterodimeric nuclease-helicase complex, HamAB. HamA, previously a protein of unknown function, is the effector nuclease. HamB is the sensor helicase. HamB constrains HamA activity during surveillance of intact dsDNA. When the HamAB complex detects DNA damage, HamB helicase activity liberates HamA, unleashing nuclease activity. Hachiman activation degrades all DNA in the cell, creating 'phantom' cells devoid of both phage and host DNA. We demonstrate Hachiman activation in the absence of phage by treatment with DNA-damaging agents, suggesting that Hachiman responds to aberrant DNA states. Phylogenetic similarities between the Hachiman helicase and eukaryotic enzymes suggest this bacterial immune system has been repurposed for diverse functions across all domains of life.

PubMed: 38464307
DOI: 10.1101/2024.02.29.582594

実験手法

ELECTRON MICROSCOPY (2.65 Å)