Hop2-Mnd1和Swi5-Sfr1使用不同的机制刺激Dmc1光纤组件
Wei Lee1, Hiroshi Iwasaki2, Hideo Tsubouchi2
1Department of Chemistry, National Taiwan University, Taiwan.
Nucleic acids research
|July 3, 2023
概括
辅助蛋白Hop2-Mnd1和Swi5-Sfr1增强了Dmc1复合酶在分离过程中在DNA上的丝组合. 这些蛋白质单独增强Dmc1的作用.
科学领域:
- * 分子生物学 * 分子生物学
- * 遗传学 遗传学是一门学科
- * 生物化学 * 生物化学
背景情况:
- * 半月变症涉及同质染色体配对和链交换,由Dmc1和Rad51重组酶介导.
- *已知裂变酵母蛋白 Swi5-Sfr1 和 Hop2-Mnd1 刺激了Dmc1介导的重组.
- *Swi5-Sfr1和Hop2-Mnd1刺激Dmc1的精确分子机制在很大程度上仍未被描述.
研究的目的:
- *阐明Hop2-Mnd1和Swi5-Sfr1刺激Dmc1重组酶活性的分子机制.
- * 调查Hop2-Mnd1和Swi5-Sfr1在Dmc1光纤组合中在单链DNA (ssDNA) 上的不同作用.
- * 确定这些辅助蛋白质的联合作用如何影响Dmc1核和线索形成.
主要方法:
- *单分子光共振能量转移 (smFRET) 实验,用于监测Dmc1光纤动态.
- *绑定粒子运动 (TPM) 试验评估Dmc1在DNA基质上的结合和组合.
- *Dmc1结合和解离速率在辅助蛋白的存在和缺乏的情况下的动态分析.
- * 顺序加法实验,以界定辅助蛋白和Dmc1.1的顺序作用.
主要成果:
- *无论是Hop2-Mnd1还是Swi5-Sfr1都会单独增强ssDNA上的Dmc1光纤组件.
- *Hop2-Mnd1和Swi5-Sfr1的联合存在导致进一步刺激Dmc1光线形成.
- *Hop2-Mnd1增加了Dmc1结合的速度 (增强核化),而Swi5-Sfr1降低了核化过程中Dmc1的解离率.
- *Hop2-Mnd1在单链/双链DNA结处促进Dmc1核化,其存在缩短了核化时间.
结论:
- *Hop2-Mnd1和Swi5-Sfr1在不同的步骤中起作用,在介质重组过程中促进Dmc1光纤组装.
- *Hop2-Mnd1的功能是招募Dmc1并促进其在DNA结处的核化.
- * Swi5-Sfr1通过减少关键核化阶段的解离来稳定Dmc1丝.
- *Dmc1活动的调节是由辅助蛋白的DNA结合特性和重组酶核化偏好决定的.
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