CRISPR/Cas system of small editing genome and special CasX protein thereof

The invention discloses a CRISPR (clustered regularly interspaced short palindromic repeats)/Cas system of a small editing genome and a special CasX protein thereof. And the CasX protein is a LesCasX protein, a VemCasX protein, an HrbCasX protein or a CkbCasX protein. The amino acid sequences of the LesCasX protein, the VemCasX protein, the HrbCasX protein and the CkbCasX protein are sequentially as shown in SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5 and SEQ ID NO: 7. Experiments prove that the CasX protein provided by the invention has the characteristics of small molecular weight, no pathogenic bacterium source and the like, is closer to physiological conditions under low salt concentration, has better DNA cleavage activity, and can be used as a novel CRISPR-Cas gene editing system which has small molecular weight and is more suitable for being wrapped by AAV. The method has an important application value. 本发明公开了一种小型编辑基因组的CRISPR/Cas系统及其专用的CasX蛋白。CasX蛋白为LesCasX蛋白、VemCasX蛋白、HrbCasX蛋白或CkbCasX蛋白。LesCasX蛋白、VemCasX