Structural highlights
Function
[CSM6_ENTI1] CRISPR (clustered regularly interspaced short palindromic repeat) is an adaptive immune system that provides protection against mobile genetic elements (viruses, transposable elements and conjugative plasmids). CRISPR clusters contain spacers, sequences complementary to antecedent mobile elements, and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA) (Probable). The type III-A Csm effector complex binds crRNA and acts as a crRNA-guided RNase, DNase and cyclic oligoadenylate synthase; binding of target RNA cognate to the crRNA is required for all activities. In a heterologous host the appropriately targeted Csm effector complex prevents growth of dsDNA phage phiNM1-gamma6. This protein is not part of the Csm effector complex (PubMed:28722012).[1] A single-strand-specific endoribonuclease (ssRNase) (PubMed:28722012). Activity is stimulated by cyclic oligoadenylates (cOA); maximal stimulation is seen with cyclic hexaadenylate (cA6) (PubMed:28722012).[2]
References
- ↑ Niewoehner O, Garcia-Doval C, Rostol JT, Berk C, Schwede F, Bigler L, Hall J, Marraffini LA, Jinek M. Type III CRISPR-Cas systems produce cyclic oligoadenylate second messengers. Nature. 2017 Aug 31;548(7669):543-548. doi: 10.1038/nature23467. Epub 2017 Jul, 19. PMID:28722012 doi:http://dx.doi.org/10.1038/nature23467
- ↑ Niewoehner O, Garcia-Doval C, Rostol JT, Berk C, Schwede F, Bigler L, Hall J, Marraffini LA, Jinek M. Type III CRISPR-Cas systems produce cyclic oligoadenylate second messengers. Nature. 2017 Aug 31;548(7669):543-548. doi: 10.1038/nature23467. Epub 2017 Jul, 19. PMID:28722012 doi:http://dx.doi.org/10.1038/nature23467