考古Hel308通过控制DNA回火的催化开关抑制了重组
Rebecca J Lever1, Emily Simmons1, Rebecca Gamble-Milner1
1School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK.
Nucleic acids research
|July 6, 2023
概括
古代生物的Hel308蛋白对基因组稳定至关重要,它使用IVa图案来控制DNA修复和重组. 这种基因的突变会增加它的活性,导致基因转换增加,但不会影响细胞活力.
科学领域:
- 遗传学 遗传学 是一个
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- Hel308螺旋酶对于古生物的基因组稳定至关重要,并且在元动物中作为HELQ保存.
- 在保持基因组稳定性方面,古Hel308的确切作用仍然不完全理解.
- 已知 Hel308 酶的催化机制,但它们在古生物中的特定功能需要进一步阐明.
研究的目的:
- 为了研究一个保存的动图 (动图IVa) 在考古Hel308.8.的功能.
- 阐明Hel308在古生物中的DNA修复和重组途径中的作用.
- 了解IVa图案如何调节Hel308.8的酶活性和细胞功能.
主要方法:
- 在体外生化测试以评估纯化Hel308.8的DNA解和链回火活动.
- 在Hel308.8中保存图案IVa的局部定向突变发生.
- 使用Hel308晶体结构进行全原子分子动力学模拟.
- 分析复合频率,基因转换,交叉事件,细胞活力和DNA损伤敏感性,在古细胞中具有突变或被删除的Hel308.
主要成果:
- 动机IVa (F/YHHAGL) 的突变导致净化Hel308.8的高活性DNA化酶和链回火活动.
- 分子动力学模拟为突变Hel308.8的改变活动提供了结构基础.
- 在体内,IVa基因突变导致基因转换 (非交叉) 重组的增加16万倍,而不会影响交叉重组,细胞活力或DNA损伤敏感性.
- 删除Hel308导致生长受损,对DNA交叉链接剂的敏感性增加,并适度增加重组.
结论:
- 考古Hel308的功能是抑制重组并促进DNA修复.
- Motif IVa 作为 RecA2 域内的催化开关,调节不同的重组和修复活动.
- 通过其双重功能,Hel308在古生物中维持基因组稳定性方面发挥着关键作用.
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