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I have many questions about the Cas9 enzyme. When the Cas9-guideRNA (crRNA and transcrRNA) complex is attached to the DNA sequence, what is the type of bond that cuts the Cas9? Does the Cas9 degrade all the sequence of DNA complementary to the guide RNA?

If the question before is "Not", then how is the sequence that is going to be cut on the DNA complementary to the guide DNA, determined? What type of enzyme the Cas9 is?

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Cas9 is an endo-deoxyribonuclease (UniProt-Q99ZW2). It also has a 3'-5' exonuclease activity by which it trims the DNA a little bit, from the cut site (but not too much).

Although, Cas9 is an endonuclease and is evolved as a mechanism of immunity against viruses (like restriction enzymes), they are not considered restriction enzymes. One of the most important differences is that the restriction enzymes do not need an RNA or a DNA as a tether to identify the target sites in the DNA; their DNA binding domains can recognize the restriction sites by themselves.

Cas9 cannot just cleave any DNA complementary to the guide RNA. It needs PAM (protospacer adjacent motifs) sequences adjacent to the target site to cleave that latter.

For details check out the wikipedia page on CRISPR or read a review.

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