核酸的Z型采用是一个多步骤的过程,
Parker J Nichols1, Jeffrey B Krall1, Morkos A Henen1,2
1Department of Biochemistry and Molecular Genetics, University of Colorado Denver School of Medicine, Aurora, Colorado 80045, United States.
Journal of the American Chemical Society
|December 22, 2023
概括
在DNA和RNA中Z-构成由Zα域稳定. 这项研究揭示了糖翻转是Z型采用的关键,支持蛋白质介导螺旋转换的"拉链模型".
科学领域:
- 分子生物学
- 生物物理
- 结构生物学
背景情况:
- 核酸 (DNA和RNA) 的左侧Z构造由Zα域稳定,这是天生的免疫蛋白的一部分.
- Zα域与Z-DNA/Z-RNA的独特几何相互作用以稳定这种更高能量的构造.
- 由蛋白质诱导的右手向左手螺旋转变的精确机制和中间步骤仍然不太清楚.
研究的目的:
- 研究核酸中采用Z-构成的机制.
- 了解Zα域在稳定Z构造中的作用.
- 阐明螺旋过渡中涉及的中间步骤.
主要方法:
- 核磁共振 (NMR) 光谱学
- 生物物理测量
- 通过Arrhenius图表计算激活能量.
主要成果:
- 在没有Zα域的情况下,DNA和RNA结构在室温和低盐度下显示了最小的短暂Z- 构造 (<0. 5%).
- 在更高的温度下观察到一种短暂的未折叠的中间体.
- 在Zα的存在下,核酸双重化的易度与Z型采用率相关.
- 糖翻转被确定为Z形式采用的最大激活能量.
结论:
- 这些发现验证了Z型采用Zα域介导的拟议"拉链模型".
- 在不太稳定或在机械应力下的双链核酸区域中,Z形态更容易被采用.
- 这项研究提供了对蛋白质诱导的核酸结构变化的机制性见解.
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