Construction and optimization of a base editor based on the MS2 system

Background Catalytic defect Cas9‐cytosine deaminase fusion is widely used in base editing. The Multiple copy numbers of the MS2 binding site (MBS) can recruit multiple MS2 coat proteins (MCPs), which are usually applied to amplify signals. Our study aimed to apply the MS2 signal amplification system to the base editing system in order to achieve simultaneous mutations of multiple bases at the target genome site.