LAUSR

Although base editors are useful tools for precise genome editing, current base editors can only convert either adenines or cytosines. We developed a dual adenine and cytosine base editor (A&C-BEmax) by fusing both deaminases with a Cas9 nickase to achieve C-to-T and A-to-G conversions at the same target site. Compared to single base editors, A&C-BEmax’s activity on adenines is slightly reduced, whereas activity on cytosines is higher and RNA off-target activity is substantially decreased. Base editors that modify both adenine and cytosine broaden the potential applications of base editing.