打破了遗传密码的退化
Inchan Kwon1, Kent Kirshenbaum, David A Tirrell
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Journal of the American Chemical Society
|June 19, 2003
概括
研究人员设计了一种酵母氨酸转移RNA (tRNA) 来改变大肠杆菌中的遗传密码. 这种修改允许在UUU编码子上用L-3-(2-naphthyl) alanine具体取代氨酸.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 遗传密码表现出退化,其中多个编码子指定相同的氨基酸.
- 转移RNA (tRNA) 和氨基酸-tRNA合成酶是将遗传信息转化为蛋白质的关键组成部分.
- 修改这些组件为改变或扩展遗传密码提供了一条途径.
研究的目的:
- 研究破解大肠杆菌遗传密码退化的可行性.
- 设计一种系统,用于将非正规氨基酸具体纳入蛋白质.
主要方法:
- 产生一个突变的酵母氨转移RNA (ytRNAPheAAA) 与一个修饰的抗.
- 大肠杆菌与人工合成的ytRNAPheAAA和一个突变的酵母fenilalanyl-tRNA合成酶的共同转化.
- 评估特定编码子 (UUU 和 UUC) 的氨基酸替代效率.
主要成果:
- 在UUU编码子中证明了用L-3-(2-naphthyl) alanine (Nal) 替代氨 (Phe) 的有效替代.
- 没有观察到UUC编码子的显著替换,表明编码子的特异性.
- 验证了工程系统选择性地改变氨基酸结合的能力.
结论:
- 这项研究成功地证明了大肠杆菌中遗传密码的有针对性的重编程.
- 可利用工程化tRNA和合成酶系统来打破遗传密码退化.
- 这种方法有可能通过新型氨基酸扩展蛋白质组.
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