<p>Base editors hold great promise in endogenous mutagenesis for genetic screening. However, the development of base editors that induce saturated multi-base conversions with diverse mutation spectrum is challenging. Here, we develop triple base editors (smACGs) that simultaneously mutagenize adenine, cytosine, and guanine within the same allele. Through screening and embedding engineered deaminase and alkyladenine DNA glycosylase variants in Cas9 structure, smACGmax is generated to catalyze robust triple-base conversion efficiencies of up to 41% across varied sequence contexts while maintaining low RNA off-target effects compared to previous dual-base editors. We apply smACGmax to enable high coverage (94%) of targeted <i>HBEGF</i> mutagenesis that identified diphtheria toxin-resistant mutations and to dissect SF3B1 variants with alternative splicing specificity via complex single, double, and triple base conversion screening. smACGmax expands base conversion capability from single and double substrates to trinucleotide level, which facilitates the generation of high-diversity and complex genetic variants, providing a useful platform for mutagenesis-based application.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

High-diversity base mutagenesis via simultaneous adenine, cytosine and guanine editing

  • Mengjia Hong,
  • Changming Luan,
  • Meng Yuan,
  • Hao Huang,
  • Xinyuan Guo,
  • Dihao Meng,
  • Molin Huang,
  • Ye Xu,
  • Shanghui Zhao,
  • Ke Chen,
  • Jiao Chen,
  • Dali Li,
  • Liang Chen

摘要

Base editors hold great promise in endogenous mutagenesis for genetic screening. However, the development of base editors that induce saturated multi-base conversions with diverse mutation spectrum is challenging. Here, we develop triple base editors (smACGs) that simultaneously mutagenize adenine, cytosine, and guanine within the same allele. Through screening and embedding engineered deaminase and alkyladenine DNA glycosylase variants in Cas9 structure, smACGmax is generated to catalyze robust triple-base conversion efficiencies of up to 41% across varied sequence contexts while maintaining low RNA off-target effects compared to previous dual-base editors. We apply smACGmax to enable high coverage (94%) of targeted HBEGF mutagenesis that identified diphtheria toxin-resistant mutations and to dissect SF3B1 variants with alternative splicing specificity via complex single, double, and triple base conversion screening. smACGmax expands base conversion capability from single and double substrates to trinucleotide level, which facilitates the generation of high-diversity and complex genetic variants, providing a useful platform for mutagenesis-based application.