在溶液中对II组内部分支站点的构造
Jörg C Schlatterer1, Samuel H Crayton, Nancy L Greenbaum
1Department of Chemistry and Biochemistry, Florida State University, 214 DLC, Tallahassee, Florida 32306-4390, USA.
Journal of the American Chemical Society
|March 23, 2006
概括
第二组内子使用域6中的特定腺素作为分支部位进行拼接. 结构研究显示,这个分支部位是螺旋外的,由内部环和金属离子稳定.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 第二组内子是催化前mRNA剪接的 ribozymes.
- 机理上的相似性表明,与真核细胞结合体体具有共同的祖先.
- 域6 (D6) 包含关键的分支部位腺素.
研究的目的:
- 阐明 ai5gamma II 组内 D6 中分支区域的结构特征.
- 确定内部循环在分支站点构造中的作用.
- 调查金属离子对分支点暴露的影响.
主要方法:
- 核磁共振 (NMR) 光谱学.核磁共振 (NMR) 光谱学.
- 使用2-aminopurine替代的光光谱学.
- 位点定向的突变发生,以删除内部循环.
主要成果:
- 支部部位腺暴露于溶剂中,这种效应由Mg2+或Ca2+增强.
- 核磁共振 (NMR) 数据表明,侧面的尿素采用了堆叠的螺旋内形状.
- 删除内部循环会导致暴露较少的分支部位,可能形成一个G-A基对.
结论:
- 提出了一个模型,其中分支部位腺是外螺旋的,旁边是内螺旋的尿液.
- 内部循环和双价金属离子对于建立这种形状至关重要.
- 这些发现提供了对II组内拼接的结构基础的见解.
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