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Publication Abstract from PubMed

Prokaryotic type III CRISPR-Cas antiviral systems employ cyclic oligoadenylate (cA(n)) signaling to activate a diverse range of auxiliary proteins that reinforce the CRISPR-Cas defense. Here we characterize a class of cA(n)-dependent effector proteins named CRISPR-Cas-associated messenger RNA (mRNA) interferase 1 (Cami1) consisting of a CRISPR-associated Rossmann fold sensor domain fused to winged helix-turn-helix and a RelE-family mRNA interferase domain. Upon activation by cyclic tetra-adenylate (cA(4)), Cami1 cleaves mRNA exposed at the ribosomal A-site thereby depleting mRNA and leading to cell growth arrest. The structures of apo-Cami1 and the ribosome-bound Cami1-cA(4) complex delineate the conformational changes that lead to Cami1 activation and the mechanism of Cami1 binding to a bacterial ribosome, revealing unexpected parallels with eukaryotic ribosome-inactivating proteins.

Ribosomal stalk-captured CARF-RelE ribonuclease inhibits translation following CRISPR signaling.,Mogila I, Tamulaitiene G, Keda K, Timinskas A, Ruksenaite A, Sasnauskas G, Venclovas C, Siksnys V, Tamulaitis G Science. 2023 Dec;382(6674):1036-1041. doi: 10.1126/science.adj2107. Epub 2023 , Nov 30. PMID:38033086^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.