一种三抗解读器阻止信使RNA中的子.
K Ito1, M Uno, Y Nakamura
1Department of Tumor Biology, Institute of Medical Science, University of Tokyo, Japan.
Nature
|February 25, 2000
概括
细菌释放因子 (RF1和RF2) 通过特定的氨基酸三来识别停止子. 这些三,就像tRNA反子一样,破译停止基,确保精确的蛋白质合成终止.
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:
- Prokaryotic 转化释放因子 RF1 和 RF2 终止了多合成.
- RF1识别了UAG/UAA,而RF2识别了UGA/UAA的停止编码.
- 这些因子读取相同和非相同的停止编码子的机制仍然不清楚.
研究的目的:
- 为了阐明由 prokaryotic 释放因子停止编码子识别的分子基础.
- 确定负责释放因子特异性的特定域和氨基酸序列.
主要方法:
- 使用交换保存域构建RF1-RF2混合释放因子.
- 基因选择以确定特异性决定性领域的功能变异.
- 在试验室释放试验中,使用纯化的释放因子和停止密码子变体进行了测试.
- 使用基类同类的停止编码子识别的分析.
主要成果:
- 在RF1-RF2杂交中的特定域互换改变了停止编码子识别特异性.
- 三蛋白Pro-Ala-Thr (在RF1) 和Ser-Pro-Phe (在RF2) 被确定为特异性的关键决定因素.
- 这些三的第一个和第三个氨基酸独立地区分了停止子的第二个和第三个纯氨基基.
- purin 的 C2 氨基组可能是区分关氨酸 (G) 和腺氨酸 (A) 的主要目标.
结论:
- 细菌释放因子利用分辨器三来停止编码子识别.
- 这三的功能类似于转移RNA中的抗,尽管它是基于蛋白质的.
- 这些发现揭示了蛋白质-RNA相互作用在解码遗传信息中的新机制.
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