NAT CELL BIO: Li's team develops an efficient cytosine editor

Cytosine base editor is a powerful genetic tool for catalyzing the conversion of cytosine to thoracic sine at a specific genomic site, and further improving editing scope and efficiency is essential for its wider applicationby inserting a non-sequence-specific single-stranded DNA binding domain of the Rad51 protein between Cas9 nickase and deaminase, the researchers produced a sequence of supercyliaside base editing sitcomsIn cell lines and mouse embryos, its activity increased significantly, and the editing window expanded in the direction of the pronucleotide adjacentin addition, hyeA3A-BE4max selectively catalyzes cytoside conversion in TC base pairs, with a wider editing range and higher activity (up to 257 times)in addition, hyeA3A-BE4max specifically produced C-T conversion without inducing a bystander mutation in the hemoglobin gene promoter, mimicking a naturally occurring gene variant to improve beta-hemoglobin disease, suggesting that the improved base editing agent has therapeutic potential