Scientists have discovered that the new gene editing tool is half the size of CRISPR-Cas9.

Recently, researchers at the Institute of Innovative Genomics at the University of California, Berkeley, usa, discovered a new gene editing tool, Cas, a minimally functional CRISPR-Cas system consisting of 1 to 70 KD Cas proteins and a CRISPR array, encoded only in the genome of giant phages, half the size of CRISPR-Cas 9, published July 16 in the journal ScienceDOI: 10.1126/science.abb1400 Cass (Cas12j) is a cas protein family encoded in the branches of giant phages, which are used by giant phages to induce bacteria to resist themselves rather than their own virusesit uses a single active site for CRISPR RNA (crRNA) processing and crRNA-directed DNA cutting to target foreign nucleic acidsresearchers first determine whether Cas can be used as a true CRISPR-Cas systemthey found that Cass is a functional phage protein and a true CRISPR-Cas effector in its natural environment, which can elicit the complementary DNA of crRNA, this single RNA system is much more compact than other active CRISPR-Cas systemsnext, the team needs to understand the identification and cleavage requirements of DNA in vitroresults show that the lysis activity of Cas can only be observed when the trace DNA is identified, and only the minimum PAM condition is required, which may facilitate broader nucleic acid testingfinally, to study whether Cas can be used in human genome editing, the researchers used Cass, which is expressed with crRNA, in heK293 cells to perform gene destruction determinationsthey found that Cas-2 and Cas-3 induced the targeted destruction of genomic-integrated-enhanced green fluorescence protein (EGFP) genes, Cas-2 with a single guided RNA is able to edit up to 33% of the cells, which is comparable to the previously reported levels of CRISPR-Cas9, CRISPR-Cas12a and CRISPR-CasXa diagram of the function of the macrophage-coded Cas in the case of its host's hyper-infection, this is not the first appearance of Casit was first discovered by Basem Al-Shayeb, a doctoral student at IGI, another lead author of the study, published in Nature on February 12, Al-Shayeb was working in a lab at the University of California, Berkeley, where Heltian FBanfield, a professor in the Department of Earth and Planetary Sciences, workedthey believe that the giant phage, which contains Cas, is a member of the giant phage that already exists and exists in a variety of environmentsrecent discovery reveals the huge gene-editing potential of Cas, providing an advantage for cell transfer and expanding the "toolbox" of gene editing more important, Cass protein brings giant phages to the forefront of human health discovery and biotechnology applications but researchers have a long way to go to optimize Cas for gene editing and to explore the best way to design guidance RNAs for targeting specific genes References: crispR-CasF from huge phages is a hypercompact genome case.