Topic summary
TracrRNA
Extracted from the Wikipedia article Trans-activating crRNA.
Type II CRISPR-Cas systems require a tracrRNA which plays a role in the maturation of crRNA. The tracrRNA is partially complementary to and base pairs with a pre-crRNA forming an RNA duplex. This is cleaved by RNase III, an RNA-specific ribonuclease, to form a crRNA/tracrRNA hybrid. This hybrid acts as a guide for the endonuclease Cas9, which cleaves the invading nucleic acid.