Compact zinc finger base editors that edit mitochondrial or nuclear DNA in vitro and in vivo

Zinc finger (ZF) arrays are programmable DNA-binding proteins. Here the authors report ZF-DddA-derived cytosine base editors (DdCBEs) and optimise their architectures to improve targeting; they apply these variants in vitro and in vivo to mitochondrial base editing and show higher editing than ZF deaminases.