関連する実験動画
Updated: Jul 1, 2026

06:59
Nanomanipulation of Single RNA Molecules by Optical Tweezers
Published on: August 20, 2014
リボソームのRNA転写中のプロモーター閉塞
Cell
|September 23, 1988
まとめ
RNAポリメラーゼIは,DNAに結合した転写開始因子 (TIF) を問題なく読み取ることができます. しかし,RNAポリメラーゼIの通過は,下流のTIF-DNA複合体を破壊し,転写を阻害する.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝子規制 遺伝子規制
- バイオケミストリー バイオケミストリー
背景:
- 転写開始因子 (TIF) はDNAと結合し,遺伝子発現の調節に不可欠です.
- RNAポリメラーゼI (Pol I) は,リボソームのRNA遺伝子を転写し,これは厳格に規制されたプロセスです.
- Pol Iとプロモーター結合因子の相互作用を理解することは,遺伝子調節の鍵です.
研究 の 目的:
- RNAポリメラーゼIがプロモーター結合転写開始因子 (TIF) を読める能力を調査する.
- TIF-DNA複合体と下流転写に対するPol I経路の影響を決定する.
- プロモーター閉塞を防止する上流端末配列の役割を明らかにする.
主な方法:
- 二次リボソームRNA遺伝子プロモーターシステムを使用した.
- アップストリームおよびダウンストリームプロモーターからの評価された転写.
- Pol I通過後のTIF-DNA複合体の完全性と足跡を分析した.
主要な成果:
- RNAポリメラーゼIは,上流のTIF結合DNAを自由に読み取る.
- 下流プロモーターを通過するRNAポリメラーゼIの通過は,転写を阻害する.
- Pol I readthroughは下流のTIF-DNA複合体を破壊し,その足跡を変更しました.
結論:
- RNAポリメラーゼIは,プロモーターに結合したTIFを克服できるが,この相互作用は結果なしではない.
- RNAポリメラーゼIの通過はTIF-DNA複合体を破壊し,下流転写に影響を与える.
- アップストリーム端末配列は,タンデム遺伝子配列におけるプロモーターオークスルーションを防ぐ可能性があります.
関連する概念動画
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...

