Lei Yang, Yanan Huo, Man Wang, Dan Zhang, Tianai Zhang, Hao Wu, Xichen Rao, Haowei Meng, Shuming Yin, Jiale Mei, Dexin Zhang, Xi Chen, Jia Lv, Meizhen Liu, Yiyun Cheng, Yuting Guan, Bo Feng, Gaojie Song, Chengqi Yi, Mingyao Liu, Fanyi Zeng, Liren Wang, Dali Li
Cytosine base editors (CBEs) are effective tools for introducing C-to-T base conversions, but their clinical applications are limited by off-target and bystander effects. Through structure-guided engineering of human APOBEC3A (A3A) deaminase, we developed highly accurate A3A-CBE (haA3A-CBE) variants that efficiently generate C-to-T conversion with a narrow editing window and near-background level of DNA and RNA off-target activity, irrespective of methylation status and sequence context. The engineered deaminase domains are compatible with PAM-relaxed SpCas9-NG variant, enabling accurate correction of pathogenic mutations in homopolymeric cytosine sites through flexible positioning of the single-guide RNAs...
March 29, 2024: Nature Chemical Biology