スプライシングエンドヌクレアゼによるプレ-tRNAの割れは,複合活性サイトを必要とします
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
まとめ
ユカリオットのtRNA-splicing endonucleaseは,核分裂細胞の核分裂細胞に作用する.
科学分野:
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
- RNA 生物学 RNA 生物学
背景:
- トランスファーRNA (tRNA) スプライシングは,真核生物における前駆体tRNAからイントロンを除去する.
- tRNA-splicing endonucleaseは,Sen54,Sen2,Sen34,およびSen15サブユニットのテトレイマーであり,イントロンの除去を触媒化する.
- 以前の研究では,Sen2とSen34がそれぞれ5'および3'分裂活性部位を含んでいることが確認された.
研究 の 目的:
- 保存された"cation-piサンドイッチ"モチーフがユカリオットtRNAスプライシングにおける役割を調査する.
- 古代のエンドヌクレアゼで確認されたこのモチーフが,真核のtRNAエンドヌクレアゼの触媒化に不可欠であるかどうかを判断する.
- ユカリオットのtRNA-splicing endonucleaseの活性部位の組成を解明する.
主な方法:
- サイト・ディレクテッド・ミュータゲネシスは,カチオン-ピサンドイッチ相互作用を妨害する.
- 5' スプライス・サイト・クリベージ・アクティビティを測定する生化学的測定法.
- ユカリオットのtRNA-splicing endonucleaseの構造と機能の分析.
主要な成果:
- Sen34サブユニットを含むクロスサブユニット相互作用によって形成される保存されたカチオン-ピサンドウィッチは,5'スプライスサイト触媒に不可欠です.
- 5'スプライス部位での触媒は,Sen2触媒三位体とSen34由来のカチオン-ピサンドイッチの両方を必要とします.
- この相互作用は,活性部位内のRNA基板の位置づけに不可欠です.
結論:
- ユカリオット型tRNAのスプライシングは,複数のサブユニットからの貢献を必要とする複合活性サイトを含む.
- カチオン-ピサンドイッチは,エウカリオットtRNA-splicingendonucleaseの以前に認識されていない機能的要素を表しています.
- このメカニズムを理解することで,RNAの処理と酵素の進化の洞察が得られます.
関連する概念動画
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...


