概括
使者RNA (mRNA) 的二次结构对于核糖体结合并不重要,但对于准确的翻译启动至关重要. 展开的mRNA允许核糖体绕过起始编码子,影响蛋白质合成的忠实性.
科学领域:
- 分子生物学分子生物学
- 生物化学 生化学
- 遗传学 遗传学 是一个
背景情况:
- 细胞mRNA的翻译启动依赖于对5'近位AUG编码子的特定识别.
- 在核糖体结合和翻译忠实性中mRNA二次结构的作用尚未完全理解.
研究的目的:
- 调查mRNA二次结构对于核糖体识别和翻译启动的必要性.
- 确定mRNA结构变化如何影响翻译忠实性和效率.
主要方法:
- 雷奥病毒mRNA被化学修改 (双硫酸盐处理,IMP合并) 以展开其二次结构.
- 用小麦胚芽核糖体进行结合试验,使用原生和未折叠的mRNA.
- 分析了原生和未折叠的mRNA上的翻译启动和子单元迁移.
主要成果:
- 未折叠的mRNA保留了结合核糖体的能力,这表明初步识别不需要二次结构.
- 核糖体不会与展开的mRNA的内部部位结合,从而保持单基质性质.
- 变质的mRNA导致40S核糖体子单元迁移到5'近位AUG编码子以后,从而降低了翻译保真度.
- 增强的mRNA二次结构 (BrUMP替代) 降低了核糖体结合效率.
结论:
- mRNA的二次结构对核糖体结合不至关重要,但通过调节40S子单元迁移,在确保翻译忠实性方面发挥着至关重要的作用.
- 二级结构调节翻译效率,增加稳定性可能会降低结合效率.
相关概念视频
Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.Ribosome Structure and AssemblyRibosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within the...
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...
Regulated mRNA Transport
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific...
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...
Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
Nucleic Acid Structure
The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA has a double-helix structure. The...
DNA Structure
DNA has a double-helix structure. The...


