5S基因内部控制区域是B型,既在溶液中自由存在,又与TFIIIAIA复合在一起
J M Gottesfeld1, J Blanco, L L Tennant
1Department of Molecular Biology, Research Institute of Scripps, La Jolla, California 92037.
Nature
|October 1, 1987
概括
这是一个Xenopus 5SRNA基因.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 遗传学 是一个遗传学.
背景情况:
- 对于转录来说,Xenopus 5S RNA基因的内部控制区域至关重要.
- 之前的一项研究提出了基于序列分析和短DNA片段的A型DNA结构.
- 这一区域结合转录因子IIIA (TFIIIA),一种结合蛋白.
研究的目的:
- 在溶液中研究Xenopus 5SRNA内部控制区域的DNA结构.
- 为了确定DNA是否采用A型构造,正如之前建议的那样.
- 为了检查TFIIIA与DNA结合时的结构变化.
主要方法:
- 循环二重化 (CD) 光谱法用于分析与TFIIIA结合部位相应的合成54-bp脱氧利贡核酸.
- 将DNA的CD光谱与已知的B型DNA光谱进行比较.
- 分析了DNA-TFIIIA复合体的CD光谱,以检测结构变化.
主要成果:
- 合成的54-bp脱氧氧核酸的CD光谱与B型DNA的CD光谱相似.
- DNA-TFIIIA复合体表现出一个未经改变的DNACD组件.
- 在TFIIIA结合后没有观察到DNA结构的严重变化.
结论:
- 克塞诺普斯5SRNA基因的内部控制区域可能存在于溶液中的B型DNA结构中.
- 结合TFIIIA不会导致DNA的显著结构变化.
- 这一发现挑战了此前在这个功能性重要区域中存在A型DNA结构的假设.
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