9WT0

CryoEM structure of one tail-fiber connected to the baseplate wedge in the contracted AlgoCIS

9WT0 の概要

• エントリーDOI: 10.2210/pdb9wt0/pdb
• EMDBエントリー: 66212
• 分子名称: PKD domain-containing protein, The baseplate protein Alg12 (2 entities in total)
• 機能のキーワード: contractile injection system, cryoem, marine bacterium, structural protein
• 由来する生物種: Algoriphagus machipongonensis; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 593787.70

構造登録者

Xu, J.,Ericson, C.F.,Toenshoff, E.R.,Pilhofer, M. (登録日: 2025-09-15, 公開日: 2026-05-06)

主引用文献

Xu, J.,Ericson, C.F.,Toenshoff, E.R.,Pilhofer, M.
Stepwise firing mechanism of an extracellular contractile injection system.
Nat Commun, 2026

PubMed Abstract: Contractile injection systems (CISs) mediate cell-cell interactions and are widespread among bacteria and archaea. These phage tail-like macromolecular machines puncture their target by a tube that is propelled by a contractile sheath. The mechanism underlying CIS firing, which starts with target binding and ends with sheath contraction, remains unclear. Here, we investigate the extracellular CIS from Algoriphagus machipongonensis (AlgoCIS) by a multimodal cryo-electron microscopy approach and structure-guided engineering, which allowed us to arrest AlgoCIS in multiple intermediate states of firing. Together with the post-firing structure, our data suggest a stepwise firing mechanism involving all structural modules: signal propagation starts with the binding of the tail-fibers, followed by opening of the cage, an expansion of the baseplate iris, and resulting in sheath contraction and the release of cap adaptor. Our study will serve as a framework for understanding the firing mechanism of diverse CISs and will facilitate the engineering of CISs for biomedical applications.

PubMed: 42031783
DOI: 10.1038/s41467-026-72240-y

実験手法

ELECTRON MICROSCOPY (3.9 Å)