IscB

In this study, the micro-base editing system developed based on the gRNA-guided endonuclease IscB was optimized, and targeted evolution techniques such as rational design and random mutation were used to screen protein variants that can improve the activity of the IscB endonuclease and high-activity gRNA variants, and finally a micro-base editing system with high editing activity was obtained. On this basis, the system was modified to develop an efficient micro-two-base editing system, the size of which is in the range of AAV delivery, and also proved its potential to correct disease sites, providing a new tool for gene editing.

本研究针对基于向导RNA（gRNA）引导的核酸酶IscB构建的微型碱基编辑系统开展优化工作，通过理性设计、随机突变等靶向进化技术，筛选得到可提升IscB核酸酶活性的蛋白变体与高活性gRNA变体，最终获得了具有高编辑活性的微型碱基编辑系统。在此基础上，本研究对该系统进行改造，开发出一款尺寸适配腺相关病毒（AAV）递送范围的高效微型双碱基编辑系统，并验证了其可用于校正疾病相关位点的应用潜力，为基因编辑领域提供了全新工具。