所有真核细胞SMC蛋白质在每个DNA循环挤出步骤中都会诱导0.6的扭曲
Richard Janissen1,2, Roman Barth1, Iain F Davidson3
1Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, 2629HZ, Netherlands.
Science advances
|December 13, 2024
概括
染色体结构维护 (SMC) 复合体通过循环挤出重塑DNA. 这三种真核细胞SMC复合体都在DNA循环挤出过程中诱导显著的负转,揭示了一个保存的机制.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
- 生物化学 生物化学
背景情况:
- 细胞利用染色体 (SMC) 蛋白质复合体的三个主要结构维护:凝聚素,凝聚素和SMC5/6.6.
- 这些复合体作为ATP依赖的运动蛋白质起作用,它们对于通过DNA循环挤出 (LE) 来进行基因组重塑至关重要.
- 在LE期间,SMCs调节DNA超级卷的精确机制仍然不完全理解.
研究的目的:
- 为了研究在循环挤出过程中由单个SMC复合体产生的DNA扭曲.
- 确定ATP水解在DNA循环挤出过程中的作用.
- 阐明不同真核细胞SMC复合体中DNA重塑的保存机制.
主要方法:
- 使用单分子磁笔测试直接测量DNA扭曲变化.
- 采用ATP水解突变体和非水解ATP类似物来探测ATPase循环.
- 在不同的DNA张力和步骤大小下,分析了每循环挤出步骤的扭曲诱导.
主要成果:
- 三种真核细胞SMC复合体 (凝聚素,凝聚素,SMC5/6) 都会在每一个LE步骤中诱导一个一致的,大的负扭曲 (~ -0.6连接数变化).
- 这种扭曲诱导独立于循环挤出步骤大小和应用的DNA张力.
- 在LE过程中,ATP结合而不是水解被确定为驱动扭曲生成和力生成的关键事件.
结论:
- 细胞SMC复合体共享DNA循环挤出的共同机制,其特点是显著的负扭曲诱导.
- ATP结合是负责DNA重塑的SMC ATPase循环中的关键步骤.
- 这种保存机制突显了真核生物中基因组组织和维护的基本方面.
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