タイロシル-tRNA合成酵素は,グループIのイントロン触媒コア内の保存されたtRNAのような構造モチーフを認識します
M G Caprara1, V Lehnert, A M Lambowitz
1Department of Molecular Genetics, The Ohio State University, Columbus 43210-1292, USA.
Cell
|December 13, 1996
まとめ
Neurospora crassaのCYT-18タンパク質は,tRNAとグループIのイントロンの両方と結合する. 構造的な類似性は,これらの分子が進化の起源を共有し,RNAの進化の洞察を明らかにすることを示唆しています.
科学分野:
- 分子生物学は分子生物学である.
- RNA 生物学 RNA 生物学
- 進化生物学の進化生物学について
背景:
- Neurospora crassaのミトコンドリアのチロシル-tRNA合成酵素 (CYT-18) タンパク質は,アミノアシレート tRNA (Tyr) とグループI イントロンスプライシングへの参加という二重な機能を有しています.
- これらの二重役割の構造的基礎を理解することは,RNA-タンパク質相互作用と触媒RNAの進化を明らかにするために不可欠です.
研究 の 目的:
- ミトコンドリア (mt) tRNAのCYT-18タンパク質の3次元結合部位と,N. crassa.の2つのグループIイントロン (LSUとND1) を比較する.
- CYT-18の二重機能の構造的基礎と,RNAの進化への影響について調査する.
主な方法:
- mt tRNA (Tyr),LSUイントロン,ND1イントロンのCYT-18結合部位の3次元モデルの構築.
- モデル構築に役立つ化学変化とRNAフットプリントデータを活用した.
主要な成果:
- 3次元モデルの重複により,tRNA (Tyr) とグループIイントロンの触媒核のCYT-18結合部位の重複が顕著であった.
- この構造的な重複は,CYT-18が異なるRNA構造に共通する結合インターフェースを示唆しています.
結論:
- この発見は,RNA-splicing因子が,アミノアシレーションで主要な役割を果たすタンパク質からどのように進化するかについての洞察を提供します.
- グループIのイントロンとtRNAの間の構造的類似性は,進化的関係を支持し,複雑な触媒RNAの進化のための一般的なメカニズムを提案する.
関連する概念動画
RNA Structure
Overview
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a...
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a...
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...
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...
tRNA Activation
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
RNA Structure
The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...
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...
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...
tRNA Activation
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...


