TY - JOUR T1 - C2c2 is a single-component programmable RNA-guided RNA-targeting CRISPR effector JF - bioRxiv DO - 10.1101/054742 SP - 054742 AU - Omar O. Abudayyeh AU - Jonathan S. Gootenberg AU - Silvana Konermann AU - Julia Joung AU - Ian M. Slaymaker AU - David B.T. Cox AU - Sergey Shmakov AU - Kira S. Makarova AU - Ekaterina Semenova AU - Leonid Minakhin AU - Konstantin Severinov AU - Aviv Regev AU - Eric S. Lander AU - Eugene V. Koonin AU - Feng Zhang Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/05/21/054742.abstract N2 - The CRISPR-Cas adaptive immune system defends microbes against foreign genetic elements via DNA or RNA-DNA interference. We characterize the Class 2 type VI-A CRISPR-Caseffector C2c2 and demonstrate its RNA-guided RNase function. C2c2 from the bacterium Leptotrichia shahii provides interference against RNA phage.In vitro biochemical analysis show that C2c2 is guided by a single crRNA and can be programmed to cleave ssRNA targets carrying complementary protospacers. In bacteria, C2c2 can be programmed to knock down specific mRNAs. Cleavage is mediated by catalytic residues in the two conserved HEPN domains, mutations in which generate catalytically inactive RNA-binding proteins. These results broaden our understanding of CRISPR-Cas systems and suggest that C2c2 can be used to develop new RNA-targeting tools. ER -