The targeting range of CRISPR–Cas9 base editors (BEs) is limited by their G/C-rich protospacer-adjacent motif (PAM) sequences. To overcome this limitation, we developed a CRISPR–Cpf1-based BE by fusing the rat cytosine deaminase APOBEC1 to a catalytically inactive version of Lachnospiraceae bacterium Cpf1. The base editor recognizes a T-rich PAM sequence and catalyzes C-to-T conversion in human cells, while inducing low levels of indels, non-C-to-T substitutions and off-target editing.
Gene Expression Omnibus
This work was supported by grants 2014CB910600 (L.Y.) from MOST; grants 31600619 (B.Y.), 31600654 (J.C.), 31471241 (L.Y.), 31730111 (L.Y.) and 91540115 (L.Y.) from NSFC; and grants 16PJ1407000 (J.C.) and 16PJ1407500 (B.Y.) from the Shanghai Municipal Science and Technology Commission.