Zhang Heng's team from Department of Biochemistry, School of Basic Medicine, Tianjin Medical University, and Tianjin Institute of Immunology, together with Deng Zengqin's team from Wuhan Institute of Virology, Chinese Academy of Sciences, recently studied and revealed the biological function and molecular mechanism of Type VII CRISPR Cas system, and clarified this potential new RNA editing tool. This research will provide the possibility for safer and more precise treatment of human related diseases, and has enormous potential value for drug development and clinical treatment. The relevant paper was published on the 14th in the British journal Nature. Zhang Heng introduced that microorganisms such as bacteria and archaea are one of the oldest forms of life on Earth. In the billions of years of changes on Earth, relying on their respective immune systems, bacteria and other microorganisms fight, balance, and survive against viruses. Among them, the CRISPR Cas system is an adaptive immune system for bacteria and archaea to resist virus invasion. By studying and utilizing this immune system, it can be applied to human cells, like antivirus software in computers, to clean up viruses in the human body or accurately "knock out" pathogenic factors in genetic diseases. According to the different Cas effector proteins, they can be divided into two categories with a total of seven types. Among them, Cas9, Cas12, and Cas13 are widely used DNA and RNA editing tools. As a candidate CRISPR Cas system, the biological function and molecular mechanism of type VII were previously unclear. The team has thoroughly elucidated the working mechanism and structural foundation of the Type VII system through research. The three unique features of the Type VII system make it a highly promising novel RNA editing tool. Zhang Heng explained that one of the main features of CRISPR tools targeting RNA is programmability, which can directly edit or degrade mutated mRNA, accurately correcting gene expression abnormalities. Unlike DNA editing, RNA editing does not produce permanent genetic changes, which reduces off target effects and potential side effects, making it safer and providing a new approach for developing precision medicine. This study characterized the function of the Type VII CRISPR Cas system, delving into its unique assembly mechanism, substrate RNA recognition, and cleavage patterns, laying the foundation for the design and development of RNA manipulation tools based on the Type VII CRISPR system in biotechnology applications Zhang Heng said. (New Society)