The CRISPR system is a prokaryotic immune system that depends on the Cascade protein complex and small guide RNAs (crRNAs). The Cascade complex, loaded with crRNA, is now characterized, the overall architecture of Cascade deduced, and the complex found to identify targets by formation of an R loop between the crRNA and dsDNA.
- Matthijs M Jore
- Magnus Lundgren
- Stan J J Brouns
