tRNA作为B. subtilis中转录反终结的积极调节者
1Department of Biochemistry and Molecular Biology, Albany Medical College, New York 12208.
Cell
|August 13, 1993
概括
细菌tRNA合成酶基因使用转录反终结进行调节. 在 tyrS 基因中改变特定的编码子改变了它的氨基酸反应,揭示了tRNA.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 基因法规 基因法规
背景情况:
- 大多数Bacillus tRNA合成酶基因是由共享的转录抗终结机制调节的.
- 个体基因对其特定氨基酸的局限性做出反应.
- mRNA领导区域显示了一个单一的氨基酸特异性编码子的保存结构.
研究的目的:
- 为了研究Bacillus tRNA合成酶基因的调节机制.
- 为了确定特定的编码子在mRNA领导序列中的作用.
- 为了确定参与基因调节的效应分子.
主要方法:
- 在Bacillus tRNA合成酶基因中对mRNA领导序列的比较分析.
- 针对 tyrS 基因领导序列的局部导向突变发生,以改变特定的编码子.
- 在不同的氨基酸限制下,基因诱导的表型分析.
- 使用lysyl-tRNA无意义抑制剂突变的抑制分析.
主要成果:
- 将 tyrS 基因编码从 UAC (氨酸) 改为 UUC (氨酸) 取消了氨酸限制诱导,并赋予了氨酸限制诱导.
- 在子上游插入额外的基并没有影响调节,这表明一种非翻译机制.
- 领导序列中的一个无意义的编码子导致了一个不可诱导的表型,这种表型可以被 lysyl-tRNA 突变抑制.
结论:
- 在mRNA领导序列中的特定编码子决定了tRNA合成酶基因的氨基酸反应.
- 监管通过非翻译机制进行.
- 转移RNA (tRNA) 在这个调节途径中充当效应分子.
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