The Cas9 protein (CRISPR-associated protein 9), derived from type II CRISPR (clustered regularly interspaced short palindromic repeats) bacterial immune systems, is becoming an essential tool for engineering the genome in diverse organisms. As an RNA-guided DNA endonuclease, Cas9 is designated to target new sites by altering its guide RNA sequence, and its development as a tool has made sequence-specific gene editing much easier. 

For details visit - https://novateinbio.com/598-crisprcas9-protein