相关实验视频
Updated: Jul 1, 2026

06:59
Nanomanipulation of Single RNA Molecules by Optical Tweezers
Published on: August 20, 2014
在核糖体RNA转录过程中促进体封闭
Cell
|September 23, 1988
概括
RNA聚合酶I可以通过DNA结合的转录启动因子 (TIF) 读取,没有问题. 然而,RNA聚合酶I的通路会破坏下游的TIF-DNA复合体,抑制转录.
科学领域:
- 分子生物学分子生物学
- 基因规则 基因规则
- 生物化学 生化学
背景情况:
- 转录启动因子 (TIF) 与DNA结合,对于调节基因表达至关重要.
- RNA聚合酶I (Pol I) 将核糖体RNA基因转录,这一过程受到严格监管.
- 了解Pol I与促进因子结合因子之间的相互作用是基因调节的关键.
研究的目的:
- 调查RNA聚合酶I通过促进体结合的转录启动因子 (TIF) 读取的能力.
- 为了确定Pol I通过对TIF-DNA复合体和下游转录的影响.
- 阐明上游终结序列在防止促进器阻塞中的作用.
主要方法:
- 使用了一种二面性核糖体RNA基因促进系统.
- 评估了来自上游和下游发起人的转录.
- 在Pol I经过后分析了TIF-DNA复合物的完整性和足迹.
主要成果:
- RNA聚合酶I可以自由地读取上游TIF结合的DNA.
- 通过下游促进体抑制转录的RNA聚合酶I的通道.
- 波尔I读透扰乱了下游的TIF-DNA复合体并改变了它的足迹.
结论:
- RNA聚合酶I可以克服促进体结合的TIF,但这种相互作用并非没有后果.
- 通过RNA聚合酶I破坏TIF-DNA复合体,影响下游转录.
- 上游终结序列可能会防止协同基因阵列中的促进器封闭.
相关概念视频
Bacterial RNA Polymerase
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Riboswitches
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...
RNA 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...
Bacterial Transcription
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Bacterial RNA Polymerase
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Transcriptional Regulation: Riboswitches
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...

