+検索条件
-Structure paper
| タイトル | Prokaryotic Schlafen proteins cleave tRNAs during type III CRISPR immunity. |
|---|---|
| ジャーナル・号・ページ | Nat Commun, Year 2026 |
| 掲載日 | 2026年7月2日 |
著者 | Pedro Weickert / Yang Liu / Jonathan Strecker / ![]() |
| PubMed 要旨 | Schlafen nucleases restrict viral infection in mammals by cleaving self RNAs, however, their function and mechanism in prokaryotic immunity is unknown. Here, we uncover CRISPR-associated Schlafen ...Schlafen nucleases restrict viral infection in mammals by cleaving self RNAs, however, their function and mechanism in prokaryotic immunity is unknown. Here, we uncover CRISPR-associated Schlafen (Cash) proteins containing a Schlafen domain fused to Csx15, an uncharacterized member of Rossmann-like nucleotide-binding sensors. Cash is activated by cyclic tetra-adenylate (cA₄) produced during type III CRISPR interference and induces cell toxicity by cleaving tRNAs, primarily in the T-loop. Cryo-electron microscopy structures of Chloroflexi bacterium Cash reveal an inactive dodecamer, the formation of a filament upon cA₄ binding to align catalytic interfaces, and the molecular basis of substrate recognition and cleavage in a tRNA-bound complex. We identify numerous families of prokaryotic Schlafen proteins associated with diverse antiviral defense systems and characterized by unique sensor domains. This work highlights tRNA depletion by Schlafen nucleases as an evolutionary recurring antiviral strategy and reveals mechanistic differences between Cash and human Schlafen members. |
リンク | Nat Commun / PubMed:42393087 |
| 手法 | EM (単粒子) |
| 解像度 | 2.45 - 2.86 Å |
| 構造データ | EMDB-73093, PDB-9ylu: EMDB-73094, PDB-9ylv: EMDB-73096, PDB-9ylx: |
| 化合物 | ![]() ChemComp-MG: |
| 由来 |
|
キーワード | RNA BINDING PROTEIN / tRNA endonuclease / cA4 activation / CRISPR associated Schlafen / Csx15 |
ムービー
コントローラー
構造ビューア
万見文献について



著者
リンク






chloroflexia (バクテリア)
キーワード