A type III-B CRISPR-Cas effector complex mediating massive target DNA destruction

Autor: Wenyuan Han, Yingjun Li, Søren Hallstrøm, Nan Peng, Malcolm F. White, Ling Deng, Wenfang Peng, Qunxin She, Jing Zhang, Yun Xiang Liang, Mingxia Feng
Přispěvatelé: BBSRC, University of St Andrews. School of Biology, University of St Andrews. Biomedical Sciences Research Complex
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Han, W, Li, Y, Deng, L, Feng, M, Peng, W, Hallstrøm, S, Zhang, J, Peng, N, Liang, Y X, White, M F & She, Q 2017, ' A type III-B CRISPR-Cas effector complex mediating massive target DNA destruction ', Nucleic Acids Research, vol. 45, no. 4, gkw1274, pp. 1983–1993 . https://doi.org/10.1093/nar/gkw1274
Nucleic Acids Research
DOI: 10.1093/nar/gkw1274
Popis: Funding: Biotechnology and Biological Sciences Research Council [BB/M000400/1 to MFW]. The CRISPR (clustered regularly interspaced short palindromic repeats) system protects archaea and bacteria by eliminating nucleic acid invaders in a crRNA-guided manner. The Sulfolobus islandicus type III-B effector Cmr-α complex targets invading nucleic acid at both RNA and DNA levels and DNA targeting relies on the directional transcription of the protospacer in vivo. To gain further insight into the involved mechanism, we purified a native effector complex of III-B Cmr-α from S. islandicus and characterized it in vitro. Cmr-α cleaved RNAs complementary to crRNA present in the complex and its ssDNA destruction activity was activated by target RNA. ssDNA cleavage required mismatches between the 5’-tag of crRNA and the 3’-flanking region of target RNA. An invader plasmid assay showed that mutation either in the HD domain (a quadruple mutation) or in the GGDD motif of theCmr-2α protein resulted in attenuation of the DNA interference in vivo. However, double mutation of the HD motif only abolished the DNase activity in vitro. Furthermore, the activated Cmr-α binary complex functioned as a highly active DNase to destroy a large excess of substrate, which could provide a powerful means to rapidly degrade replicating viral DNA. Publisher PDF
Databáze: OpenAIRE