相关实验视频
Updated: Jul 20, 2025
06:59
Nanomanipulation of Single RNA Molecules by Optical Tweezers
Published on: August 20, 2014
14.9K
在单个分子水平上,将SAM/SAH核开关的折叠动态和功能联系起来
Ting-Wei Liao1, Lin Huang2, Timothy J Wilson3
1Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA.
Nucleic acids research
|July 31, 2023
概括
细菌的 рибо开关通过连接体结合来调节基因表达. 这项研究揭示了共转录折叠如何影响SAM/SAH рибо开关功能,影响连接体结合和翻译调节.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 遗传学 是一个遗传学.
背景情况:
- 带开关是控制基因表达的mRNA调节元件.
- 连接物结合会诱导 рибо交换机的结构变化.
- 在SAM/SAH核突变器调节基因表达,以响应S-adenosylmethionine/S-adenosylhomocysteine.
研究的目的:
- 使用单分子Förster共振能量转移 (smFRET) 绘制SAM/SAH核电交换机的结构格局.
- 调查共转录折叠如何影响 рибо开关的翻译调节功能.
- 识别关键的结构元素,涉及连接体结合和构造变化.
主要方法:
- 单分子福斯特共振能量转移 (smFRET) 光谱学.
- 现场定向的突变发生以探测结构元素.
- 分析不同折叠条件下的核糖体结合部位可访问性 (预折叠与共转录折叠).
主要成果:
- 带状交换机折叠是异质的,具有崎的构造格局,允许连接物绑定构造样本,即使没有连接物.
- 干添加改变了景观,有利于干结合的形状.
- 一个伪结螺旋被确定为关键的无联体构造和响应性.
- 同转录折叠导致初始形状不那么紧,暴露了Shine-Dalgarno序列,并由于缓慢平衡而降低了有效的连接体亲和力.
结论:
- SAM/SAH 核开关表现出复杂的折叠动态,并根据连接体结合而调整其形状.
- 同转录折叠通过改变初始形状和减缓平衡来显著影响 рибо开关的调节功能.
- 了解这些动态对于理解细菌中的基因表达调节至关重要.
相关概念视频
01:56Riboswitches
8.2K
Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
8.2K
01:23Transcriptional Regulation: Riboswitches
61
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...
61
01:29Translational Regulation
45
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
45
01:23Types of RNA
64.0K
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
64.0K
02:28Leaky Scanning
5.2K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.2K
01:44Termination of Translation
25.5K
The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
25.5K