Circularly permuted and PAM-modified Cas9 variants broaden the targeting scope of base editors
Circularly permuted and PAM-modified Cas9 variants broaden the targeting scope of base editors
复制标题
DOI：
10.1038/s41587-019-0134-y
复制
发表时间：
2019-06-01
影响因子：
46.9
通讯作者：
Liu, David R.
中科院分区：
文献类型：
--
作者：
Huang, Tony P.;Zhao, Kevin T.;Liu, David R.
碱基编辑要求靶序列满足Cas9结构域的原型间隔区相邻基序要求，并且靶核苷酸位于碱基编辑器的编辑窗口内。为了增加碱基编辑器的靶向范围，我们设计了六种优化的腺嘌呤碱基编辑器（ABEmax变体），其使用与非NGG原型间隔区相邻基序相容的SpCas 9变体。为了增加可以在原型间隔区内修饰的靶碱基的范围，我们使用环状排列的Cas9变体来产生四个胞嘧啶和四个腺嘌呤碱基编辑器，其中编辑窗口从相似的4-5个核苷酸扩展到高达相似的8-9个核苷酸，并减少副产物形成。这组碱基编辑器提高了胞嘧啶和腺嘌呤碱基编辑的靶向范围。
Base editing requires that the target sequence satisfy the protospacer adjacent motif requirement of the Cas9 domain and that the target nucleotide be located within the editing window of the base editor. To increase the targeting scope of base editors, we engineered six optimized adenine base editors (ABEmax variants) that use SpCas9 variants compatible with non-NGG protospacer adjacent motifs. To increase the range of target bases that can be modified within the protospacer, we use circularly permuted Cas9 variants to produce four cytosine and four adenine base editors with an editing window expanded from similar to 4-5 nucleotides to up to similar to 8-9 nucleotides and reduced byproduct formation. This set of base editors improves the targeting scope of cytosine and adenine base editing.