Cas9 Sandbox: Difference between revisions

[[Cas9]] is the RNA-guided [[DNA endonuclease]] used by the CRISPR (clustered regularly interspaced short palindromic repeats)-associated systems to generate double-strand DNA breaks in the invading DNA during an adaptive bacterial immune response.  Three different types of CRISPR mechanisms have been discovered, however, only type II CRISPR systems are heavily researched. In vivo, [[Cas9]] requires CRISPR RNA (crRNA) and trans-activating crRNA (tracrRNA) to guide the endonuclease toward invading DNA based on the complementary sequence recognition of these RNAs. Cas9 then targets and cleaves foreign DNA to interfere with viral replication. The CRISPR-associated endonuclease <scene name='71/714945/Pam_interaction/9'>Cas9</scene> has been exploited for use in genome editing systems. In such systems, an engineered single-guide RNA (sgRNA) is used to perform the function of crRNA-tracRNA complex to target double-stranded breaks in genomic DNA. Depending on what repair pathway is triggered, often dictated by the inclusion of additional engineered components, the targeted site either is disrupted or incorporates additional genetic sequences. <ref>PMID:24906146</ref>