6vm5

Structural highlights

Function

CAP4_MOROS CBASS (cyclic oligonucleotide-based antiphage signaling system) provides immunity against bacteriophage. The CD-NTase protein synthesizes cyclic nucleotides in response to infection; these serve as specific second messenger signals. The signals activate a diverse range of effectors, leading to bacterial cell death and thus abortive phage infection (Probable). A type II-C CBASS system (PubMed:32839535).^{[1] [2]} Probably in the presence of its endogenous cyclic nucleotide (synthesized by the cognate CD-NTase protein in the CBASS operon), or of 2',3',3'-cyclic AMP-AMP-AMP (cAAA) synthesized by Acinetobacter sp. ATCC 27244, endonucleolytically degrades dsDNA in a non-sequence specific manner. It is not activated by other cyclic nucleotides.^[3]

References

1. ↑ Millman A, Melamed S, Amitai G, Sorek R. Diversity and classification of cyclic-oligonucleotide-based anti-phage signalling systems. Nat Microbiol. 2020 Dec;5(12):1608-1615. doi: 10.1038/s41564-020-0777-y. Epub, 2020 Aug 24. PMID:32839535 doi:http://dx.doi.org/10.1038/s41564-020-0777-y
2. ↑ Lowey B, Whiteley AT, Keszei AFA, Morehouse BR, Mathews IT, Antine SP, Cabrera VJ, Kashin D, Niemann P, Jain M, Schwede F, Mekalanos JJ, Shao S, Lee ASY, Kranzusch PJ. CBASS Immunity Uses CARF-Related Effectors to Sense 3'-5'- and 2'-5'-Linked Cyclic Oligonucleotide Signals and Protect Bacteria from Phage Infection. Cell. 2020 Jun 4. pii: S0092-8674(20)30614-0. doi: 10.1016/j.cell.2020.05.019. PMID:32544385 doi:http://dx.doi.org/10.1016/j.cell.2020.05.019
3. ↑ Lowey B, Whiteley AT, Keszei AFA, Morehouse BR, Mathews IT, Antine SP, Cabrera VJ, Kashin D, Niemann P, Jain M, Schwede F, Mekalanos JJ, Shao S, Lee ASY, Kranzusch PJ. CBASS Immunity Uses CARF-Related Effectors to Sense 3'-5'- and 2'-5'-Linked Cyclic Oligonucleotide Signals and Protect Bacteria from Phage Infection. Cell. 2020 Jun 4. pii: S0092-8674(20)30614-0. doi: 10.1016/j.cell.2020.05.019. PMID:32544385 doi:http://dx.doi.org/10.1016/j.cell.2020.05.019