在酵母tRNA拼接中对基质的识别和拼接部位的确定
Cell
|November 18, 1988
概括
这项研究揭示了酵母tRNA内核酶如何选择拼接地点. 反杆干,而不是内核本身,决定了特异性,确保在tRNA成熟过程中准确地去除内核.
科学领域:
- 分子生物学分子生物学
- 处理RNA处理RNA处理
- 酶学 是一种酶学.
背景情况:
- 在Saccharomyces cerevisiae (酵母菌) 中,转移RNA (tRNA) 内子精确地位于抗环中.
- 预tRNA成熟涉及一个内核酶和一个结合酶,内核酶能够独立,准确的内核切除.
研究的目的:
- 阐明tRNA内核酶采用的拼接部位选择机制.
- 测试内核酶识别保存的成熟tRNA域并使用固定的距离来识别拼接位的假设.
主要方法:
- 使用菌体T7RNA聚合酶合成前体tRNA (tRNA前).
- 引入了特定突变 (C56,U8) 并在前tRNA中进行了插入/删除突变.
- 评估了这些突变对内核酶识别和拼接特异性的影响.
主要成果:
- 在位置C56和U8的突变显著损害了前tRNA的内核酶识别.
- 插入和删除突变表明,抗杆茎是拼接特异性的关键决定因素.
- 发现内子的序列和二次结构是选择拼接地点的次要因素.
结论:
- 酵母tRNA内核酶主要识别成熟tRNA域的保存特征.
- 拼接部位的识别是由成熟域的固定距离决定的,而抗杆茎起着至关重要的作用.
- 反杆茎,而不是内子序列或结构,决定了tRNA拼接的特异性.
相关概念视频
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
RNA Splicing
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Transfer RNA Synthesis
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
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Alternative RNA Splicing
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
Pre-mRNA Processing: RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
Alternative RNA Splicing
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...


