从tRNAile和mupirocin的ile-tRNA合成酶结构对编辑的洞察
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.
概括
黄金葡萄球菌异核素转移RNA合成酶 (IleRS) 使用不同的活性位点进行氨基酸附着和错误校正. 它的结构揭示了tRNA (Ile) 如何改变形状以使IleRS正常运行.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 单核糖转移RNA合成酶 (IleRS) 对于蛋白质合成至关重要,它将单核糖与其同源tRNA结合在一起.
- IleRS既具有用于氨基化的合成活性位点,也具有用于化不正确氨基酸附着的编辑活性位点.
研究的目的:
- 阐明IleRS功能的结构基础,包括其与tRNA (Ile) 和药物Mupirocin的相互作用.
- 了解tRNA (Ile) 所需的构造变化,以访问IleRS.的合成和编辑活性位点.
主要方法:
- 在2.2安格斯特罗姆分辨率的X射线晶体学.
- 用tRNA (Ile) 和mupirocin.complexed复合的Staphylococcus aureus IleRS的结构分析
主要成果:
- 晶体结构显示tRNA (Ile) 呈 A 形形态,其 3' 终端位于编辑活性部位.
- 推测,tRNA受体链的毛形状,类似于在tRNA(Gln) -合成酶复合体中观察到的形状,是定位3'终端在合成活性部位所必需的.
结论:
- 在IleRS复合体中的tRNA (Ile) 的独特构造突出显示了双位点酶活性的动态结构要求.
- 在IleRS中用于氨基酸编辑的合成和编辑站点之间的提议的穿机制类似于DNA聚合酶编辑机制.
相关概念视频
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...


