铁基-tRNA合成酶识别了I组内核催化核中保存的tRNA类结构动图
M G Caprara1, V Lehnert, A M Lambowitz
1Department of Molecular Genetics, The Ohio State University, Columbus 43210-1292, USA.
Cell
|December 13, 1996
概括
在Neurospora crassa中,CYT-18蛋白与tRNA和I组内子结合. 结构上的相似性表明,这些分子可能具有共同的进化起源,揭示了对RNA进化的洞察力.
科学领域:
- 分子生物学分子生物学
- 在RNA生物学,RNA生物学.
- 进化生物学 进化生物学
背景情况:
- 神经的线粒体铁基-tRNA合成酶 (CYT-18) 蛋白质表现出双重功能:氨基化tRNA (Tyr) 和参与I组内拼接.
- 了解这些双重作用的结构基础对于阐明RNA-蛋白相互作用和催化RNA的演变至关重要.
研究的目的:
- 为了比较CYT-18蛋白在线粒体 (mt) tRNA (Tyr) 和来自N. crassa的两个I组内核 (LSU和ND1) 上的三维结合位点.
- 研究CYT-18双重功能的结构基础及其对RNA进化的影响.
主要方法:
- 在mt tRNA (Tyr),LSU内核和ND1内核上构建CYT-18结合点的三维模型.
- 利用化学修饰和RNA足迹数据来告知模型的构建.
主要成果:
- 三维模型的叠加揭示了tRNA (Tyr) 和I组内子的催化核之间的CYT-18结合点的显著重叠.
- 这种结构重叠表明CYT-18在不同的RNA结构上具有共同的结合接口.
结论:
- 这些发现提供了关于RNA剪接因子如何从蛋白质中演变的见解,这种蛋白质在氨基化中起着主要作用.
- I组内子和tRNA之间的结构相似性支持进化关系,并提出复杂的催化RNA进化的一般机制.
相关概念视频
01:23RNA 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...
02:36Transfer 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...
02:26tRNA 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...
01:19RNA 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...
02:36Transfer 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...
02:26tRNA 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...