Cas9

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.

The CRISPR-associated endonuclease Cas9 has been exploited for use in genome editing systems. In such systems, an engineered single-guide RNA (sgRNA) is used 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.

Movie from the McGovern Institute for Brain Research at MIT This video, by Paul Andersen, explains how the CRISPR/Cas immune system was identified in bacteria and how the CRISPR/Cas9 system was developed to edit genomes.

Movie from the McGovern Institute for Brain Research at MIT This animation depicts the CRISPR-Cas9 method for genome editing – a powerful new technology with many applications in biomedical research, including the potential to treat human genetic disease.

Articles in Proteopedia concerning Cas9 include:

• Brett Thumm's Student Project page on Cas9

3D structures of Cas93D structures of Cas9

Streptococcus pyogenes Cas9Streptococcus pyogenes Cas9

• 4un3, 4un4, and 4un5 - S. pyogenes Cas9 bound to sgRNA and target DNA
• 4oo8 - S. pyogenes Cas9 bound to sgRNA and target DNA
• 4cmp
• 4cmq - Mn²⁺-bound S. pyogenes Cas9

Actinomyces naeslundii Cas9Actinomyces naeslundii Cas9

• 4oge
• 4ogc - Mn²⁺-bound A.s naeslundii Cas9

See AlsoSee Also

H-N-H motif