Genome engineering

Better editors

Nat. Methods 17, 600–604 (2020)

Base editors that direct deaminases to specific genome sites via CRISPR-system enzymes have gained recent attention due to precision base editing without induction of DNA double-strand breaks. However, potential off-target effects on both DNA and RNA may complicate biotechnological and therapeutic applications. To obtain cytosine base editors (CBEs) with increased specificity, Zuo et al. constructed variants of rAPOBEC1, a widely used cytidine deaminase component in CBE, within regions related to DNA and RNA editing activity. Four variants with single or double mutations near putative DNA-binding sites and/or hydrophobic sites required for RNA binding exhibited decreased DNA and RNA off-target effects in embryos and HEK293T cells, yet maintained on-target editing activity. Interestingly, the on-target activity of the variants could be further enhanced by addition of an N-terminal nuclear localization signal and codon optimization. The resulting optimized variant YE1-BE3-FNLS had on-target editing activity comparable to that of the current best base editors, with a nearly basal level of off-target edits. This study demonstrates the use of rational design to improve the performance of base editors for further applications.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Yiyun Song.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Song, Y. Better editors. Nat Chem Biol 16, 712 (2020). https://doi.org/10.1038/s41589-020-0583-0

Download citation

Search

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing