相关实验视频
Updated: Aug 5, 2026
07:46
An In Vitro Assay to Detect tRNA-Isopentenyl Transferase Activity
Published on: October 8, 2018
概括
成熟转移RNA (tRNA) 的合成涉及前体处理和核酸修饰,但这些事件的确切序列和功能在很大程度上是未知的. 对tRNA修饰酶的进一步研究对于了解tRNA在生物过程中的作用至关重要.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 转移RNA (tRNA) 基因被转录成前体分子,需要处理和修改才能成为成熟的功能性tRNA.
- 这些前体分子在两端都有额外的核酸,并且缺乏成熟tRNA中发现的修饰核酸.
研究的目的:
- 阐明参与成熟tRNA合成的分子事件和酶途径.
- 研究改性核酸在tRNA功能中的作用及其在蛋白质合成之外的细胞过程中的潜在参与.
主要方法:
- 对前体tRNA处理和修改的实验研究.
- 检测和表征参与tRNA成熟的酶,包括修剪酶和tRNA修饰酶.
- 对tRNA-蛋白相互作用的分析,重点是tRNA修饰酶和氨基酸-tRNA合成酶.
主要成果:
- 特定的核酶将前体tRNA切割到正确的大小,并且可以在转录后添加C-C-A序列.
- 各种酶修改tRNA基和糖,但这些修改的顺序和它们对tRNA功能的必要性尚未完全理解.
- 一些修改后的核酸可能对核糖体介导的蛋白质合成至关重要,而另一些可能会提高其速率或在其他细胞过程中发挥作用.
结论:
- 在tRNA合成中切割和修改事件的精确序列仍然在很大程度上是未知的.
- 大多数tRNA中修饰核酸的生物功能仍然需要阐明,人们猜测它们在病毒感染,细胞分化和激素作用中的作用.
- 研究tRNA修饰酶的突变体和理解tRNA-蛋白相互作用是破译tRNA功能及其更广泛的生物学意义的关键.
相关概念视频
02:43Nucleic acids
Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell's genetic blueprint and carry instructions for its functioning.
DNA and RNA
The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes, the...
DNA and RNA
The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the genetic material in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is in the nucleus of eukaryotes and in the organelles, chloroplasts, and mitochondria. In prokaryotes, the...
02:01pre-mRNA Processing
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 to it (7-Methyl guanosine). This 5’ cap helps the...
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 to it (7-Methyl guanosine). This 5’ cap helps the...
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...
02:23RNA Editing
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
01:35Pre-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...
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...