定向进化突变增强了腺基编辑器ABE8e的DNA结合亲和力和蛋白质稳定性
Haixia Zhu1, Lei Wang1, Ying Wang1
1State Key Laboratory of Genetic Engineering, Shanghai Engineering Research Center of Industrial Microorganisms, MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai, 200438, China.
Cellular and molecular life sciences : CMLS
|June 14, 2024
概括
定向进化突变通过增加DNA结合和蛋白质稳定性来增强腺基编辑器 (ABEs). 在TadA8e中的关键突变改善了ABE8e.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 生物工程是生物工程.
背景情况:
- 腺基编辑器 (ABEs) 使用CRISPR将A:T基对转换为G:C. Cas尼克酶和脱氨酶.
- 一种进化的变种ABE8e,由于其除氨酶TadA8e.e中的八种突变,表现出增强的基编辑活性.
- 这些特定突变对ABE8e性能的功能影响在很大程度上仍未被描述.
研究的目的:
- 阐明定向进化突变在腺基编辑器的催化活性和稳定性中的作用.
- 探究ABE8e增强的DNA结合亲和力和编辑效率背后的分子机制.
主要方法:
- 分子动力学 (MD) 模拟来分析DNA结合相互作用和蛋白质动力学.
- 使用微尺度热泳 (MST) 进行实验验证,以评估DNA结合亲和力.
- 在体内逆转基因突变实验,以确认已识别的突变的功能意义.
主要成果:
- MD模拟显示,TadA8e表现出比TadA7.10更高的DNA结合亲和力,这是由于DNA结合区域的正电荷密度增加.
- 突变R111,N119和N167被确定为增强DNA结合的关键突变,由MST和体内实验证实.
- 定向进化突变显著改善了TadA8e (~12°C) 和ABE8e (~9°C) 的热稳定性.
结论:
- 定向进化突变通过改善与DNA的静电相互作用来增强ABE8e的基质结合能力.
- 这些突变还增加了蛋白质的稳定性,有助于ABE8e的整体性能提高.
- 这些发现为进一步优化腺基编辑系统提供了合理的基础.
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