tRNAileとmupirocinを用いたile-tRNA合成酵素構造からの編集に関する洞察
L F Silvian1, J Wang, T A Steitz
1Department of Molecular Biophysics, Yale University, and Howard Hughes Medical Institute, New Haven, CT 06520-8114, USA.
まとめ
Staphylococcus aureus isoleucyl-transfer RNA synthetase (IleRS) は,アミノ酸の結合とエラー補正のために異なる活性サイトを使用しています. その構造は,IleRSが正しく機能するために,tRNA (Ile) がどのように形を変えなければならないかを明らかにします.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
背景:
- イソルエキュル転送RNA合成酵素 (IleRS) は,イソルエキュリンを同種tRNAに結合させ,タンパク質合成に不可欠です.
- IleRSは,アミノアシレーションのための合成活性サイトと,誤ったアミノ酸結合を水解するための編集活性サイトの両方を備えています.
研究 の 目的:
- IleRS機能の構造的基礎を明らかにし,tRNA ((Ile) と薬剤ムピロシンとの相互作用を含む.
- IleRS.の合成および編集活性サイトの両方にアクセスするために tRNA (Ile) に必要な構成変化を理解する.
主な方法:
- 2.2アングストームの解像度のX線結晶学.
- tRNA ((Ile) とMupirocin.で複合したStaphylococcus aureus IleRSの構造分析
主要な成果:
- 結晶構造は,編集活性部位に3'端が配置されているA型形状のtRNA (Ile) を明らかにした.
- tRNA (((Gln)) -合成酵素複合体において観察されたものと類似した,tRNA受容体鎖のヘアピン形状は,合成活性部位における3'末端の位置づけのために必要であると提案されている.
結論:
- IleRS複合体内のtRNA ((Ile)) の独特な構成は,二重サイト酵素活性に対するダイナミックな構造的要件を強調しています.
- IleRSにおけるアミノ酸編集のための合成サイトと編集サイト間の提案されたシャトルメカニズムは,DNAポリメラーゼ編集メカニズムに類似しています.
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...


