剪接内核酶对前tRNAs的裂变需要一个复合活性位点
Christopher R Trotta1, Sergey V Paushkin, Meenal Patel
1PTC Therapeutics, 100 Corporate Court, South Plainfield, New Jersey 07080, USA. ctrotta@ptcbio.com
Nature
|May 20, 2006
概括
在真核中,tRNA剪接的内核酶.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 在RNA生物学,RNA生物学.
背景情况:
- 转移RNA (tRNA) 拼接在真核生物中从前体tRNA中去除内子.
- tRNA拼接内核酶是Sen54,Sen2,Sen34和Sen15子单元的四聚体,催化了内核去除.
- 之前的研究发现,Sen2和Sen34分别含有5'和3'分裂活性位点.
研究的目的:
- 为了研究一个保存的"子-pi三明治"图案在真核tRNA拼接中的作用.
- 确定这种在古老核内核酶中发现的基因是否对真核tRNA核内核酶催化非常重要.
- 阐明真核tRNA拼接内核酶中活性位点的组成.
主要方法:
- 局部导向的突变发生,以扰乱阴离子-PI三明治相互作用.
- 生物化学测试以测量5'拼接部位切割活性.
- 对真核tRNA拼接内核酶结构和功能的分析.
主要成果:
- 通过涉及Sen34子单元的交叉子单元相互作用形成的保存的阴离子-pi三明治,对于5'拼接点催化是至关重要的.
- 在5'拼接部位的催化需要Sen2催化三元和Sen34衍生的阴离子-pi三明治.
- 这种相互作用对于将RNA基质定位在活性部位内至关重要.
结论:
- 细胞tRNA拼接涉及一个复合活性位点,需要来自多个子单元的贡献.
- 阴离子-π三明治代表了以前未被识别的功能元素在真核tRNA-splicing内核酶.
- 了解这种机制可以了解RNA处理和酶进化.
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
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: Modification of pre-mRNA Ends
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 (7-methyl guanosine). This 5' cap helps the cell...
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 (7-methyl guanosine). This 5' cap helps the cell...
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...


