不变的U5 snRNA循环1序列对于酵母中mRNA前拼接的第一个催化步骤是无需的
R T O'Keefe1, C Norman, A J Newman
1MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
Cell
|August 23, 1996
概括
小核RNA循环U5对于前传递 RNA 拼接的第一步是不必要的. 然而,它对于第二个催化步骤中的接中间体至关重要,尽管可以容忍突变.
科学领域:
- 分子生物学分子生物学
- 在RNA生物学,RNA生物学.
- 生物化学 生物化学
背景情况:
- 预mRNA剪接是基因表达的一个基本过程.
- U5小核RNA (snRNA) 在结合体功能中起着已知的作用.
- 假设不变的U5循环1与5'拼接点相互作用.
研究的目的:
- 研究U5 snRNA在mRNA前拼接的催化步骤中的作用.
- 为了确定U5循环1是否对于spliceosome催化是必要的.
- 分析U5循环突变对拼接效率的影响.
主要方法:
- 开发一种用于mRNA前拼接的体外溶解系统.
- U5 snRNA循环的局部定向突变发生 1.
- 使用复合系统对催化步骤的分析.
主要成果:
- 第一个催化步骤 (转化) 正确地在没有U5循环1的情况下进行.
- 在第一阶段,U5循环1并不是spliceosomal活性部位的重要组成部分.
- 第二个催化步骤依赖于U5循环1进行绑定,但耐受突变.
结论:
- 对于第一个拼接催化,U5循环1是不可用的.
- 通过稳定中间体,U5循环1对于第二次拼接催化非常重要.
- U5循环1的不变序列显示了第二步中对突变的意想不到的耐受性.
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...
pre-mRNA Processing
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
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...
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...


