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-Structure paper
タイトル | Activation of Thoeris antiviral system via SIR2 effector filament assembly. |
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ジャーナル・号・ページ | Nature, Vol. 627, Issue 8003, Page 431-436, Year 2024 |
掲載日 | 2024年2月21日 |
著者 | Giedre Tamulaitiene / Dziugas Sabonis / Giedrius Sasnauskas / Audrone Ruksenaite / Arunas Silanskas / Carmel Avraham / Gal Ofir / Rotem Sorek / Mindaugas Zaremba / Virginijus Siksnys / |
PubMed 要旨 | To survive bacteriophage (phage) infections, bacteria developed numerous anti-phage defence systems. Some of them (for example, type III CRISPR-Cas, CBASS, Pycsar and Thoeris) consist of two modules: ...To survive bacteriophage (phage) infections, bacteria developed numerous anti-phage defence systems. Some of them (for example, type III CRISPR-Cas, CBASS, Pycsar and Thoeris) consist of two modules: a sensor responsible for infection recognition and an effector that stops viral replication by destroying key cellular components. In the Thoeris system, a Toll/interleukin-1 receptor (TIR)-domain protein, ThsB, acts as a sensor that synthesizes an isomer of cyclic ADP ribose, 1''-3' glycocyclic ADP ribose (gcADPR), which is bound in the Smf/DprA-LOG (SLOG) domain of the ThsA effector and activates the silent information regulator 2 (SIR2)-domain-mediated hydrolysis of a key cell metabolite, NAD (refs. ). Although the structure of ThsA has been solved, the ThsA activation mechanism remained incompletely understood. Here we show that 1''-3' gcADPR, synthesized in vitro by the dimeric ThsB' protein, binds to the ThsA SLOG domain, thereby activating ThsA by triggering helical filament assembly of ThsA tetramers. The cryogenic electron microscopy (cryo-EM) structure of activated ThsA revealed that filament assembly stabilizes the active conformation of the ThsA SIR2 domain, enabling rapid NAD depletion. Furthermore, we demonstrate that filament formation enables a switch-like response of ThsA to the 1''-3' gcADPR signal. |
リンク | Nature / PubMed:38383786 |
手法 | EM (らせん対称) / X線回折 |
解像度 | 2.75 - 3.1 Å |
構造データ | EMDB-16233, PDB-8bto: EMDB-16234, PDB-8btp: PDB-8btn: |
化合物 | ChemComp-OJC: ChemComp-NAD:
ChemComp-RK3: ChemComp-ENA: |
由来 |
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キーワード | HYDROLASE / Thoeris / ThsB / TIR domain / SIR2 domain / SLOG domain / 3'cADPR |