8T66

cA6 bound Cam1

8T66 の概要

• エントリーDOI: 10.2210/pdb8t66/pdb
• 分子名称: Cam1, RNA (5'-R(P*AP*AP*AP*AP*A)-3') (3 entities in total)
• 機能のキーワード: carf, saved, membrane, crispr, cyclic adenylate, immune system, immune system-rna complex, immune system/rna
• 由来する生物種: Nitrosococcus halophilus Nc 4; 詳細
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 37795.14

構造登録者

Yu, Y.,Patel, D.J. (登録日: 2023-06-15, 公開日: 2024-01-10, 最終更新日: 2024-02-07)

主引用文献

Baca, C.F.,Yu, Y.,Rostol, J.T.,Majumder, P.,Patel, D.J.,Marraffini, L.A.
The CRISPR effector Cam1 mediates membrane depolarization for phage defence.
Nature, 625:797-804, 2024

PubMed Abstract: Prokaryotic type III CRISPR-Cas systems provide immunity against viruses and plasmids using CRISPR-associated Rossman fold (CARF) protein effectors. Recognition of transcripts of these invaders with sequences that are complementary to CRISPR RNA guides leads to the production of cyclic oligoadenylate second messengers, which bind CARF domains and trigger the activity of an effector domain. Whereas most effectors degrade host and invader nucleic acids, some are predicted to contain transmembrane helices without an enzymatic function. Whether and how these CARF-transmembrane helix fusion proteins facilitate the type III CRISPR-Cas immune response remains unknown. Here we investigate the role of cyclic oligoadenylate-activated membrane protein 1 (Cam1) during type III CRISPR immunity. Structural and biochemical analyses reveal that the CARF domains of a Cam1 dimer bind cyclic tetra-adenylate second messengers. In vivo, Cam1 localizes to the membrane, is predicted to form a tetrameric transmembrane pore, and provides defence against viral infection through the induction of membrane depolarization and growth arrest. These results reveal that CRISPR immunity does not always operate through the degradation of nucleic acids, but is instead mediated via a wider range of cellular responses.

PubMed: 38200316
DOI: 10.1038/s41586-023-06902-y

実験手法

X-RAY DIFFRACTION (1.85 Å)