関連する実験動画
Updated: May 11, 2026

11:22
Measuring the Kinetics of mRNA Transcription in Single Living Cells
Published on: August 25, 2011
まとめ
循環型AMP受容体タンパク質 (CRP) は,重複するDNA結合部位から積極的に除去することによって,RNAポリメラーゼをラックプロモーターにリダイレクトします. この相互作用は,ポリメラーゼがDNAテンプレートを去ってプロモーターを再結合することを含む.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
- バイオケミストリー バイオケミストリー
背景:
- ラックプロモーターは,遺伝子発現の重要な規制要素です.
- RNAポリメラーゼがプロモーターに結合すると,転写が始まります.
- 循環型AMP受容体タンパク質 (CRP) は,転写開始を調節することが知られている.
研究 の 目的:
- ラックプロモーターにRNAポリメラーゼの侵入のメカニズムを解明する.
- この過程におけるP2相互作用部位とCRPの役割を調査する.
主な方法:
- インビトロ結合測定法.
- ポリメラーゼの動きを研究するためのテンプレート競争実験.
- ラックプロモーターであるRNAポリメラーゼとCRPとの相互作用を調査する.
主要な成果:
- P2部位でのRNAポリメラーゼ結合は,プロモーターへのスライドにつながらない.
- RNAポリメラーゼは,プロモーターを再結合するためにDNAから解離する必要があります.
- CRPはP2からポリメラーゼを積極的に除去し,プロモーターへの結合を促進します.
結論:
- CRPがDNAに結合すると,プロモーターをクリアし,効率的なRNAポリメラーゼ結合のためにそれを修正します.
- ラックプロモーターへのRNAポリメラーゼの侵入は,CRPによって促進される解離と再結合を含みます.
関連する概念動画
Operons
Prokaryotes can control gene expression through operons—DNA sequences consisting of regulatory elements and clustered, functionally related protein-coding genes. Operons use a single promoter sequence to initiate transcription of a gene cluster (i.e., a group of structural genes) into a single mRNA molecule. The terminator sequence ends transcription. An operator sequence, located between the promoter and structural genes, prohibits the operon’s transcriptional activity if bound by a repressor...
Prokaryotic Transcriptional Activators and Repressors
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
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:
Transcription Initiation
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
Operon Model
The operon model represents a fundamental mechanism of gene regulation in prokaryotes, enabling coordinated expression of genes involved in related metabolic or functional pathways. Operons consist of structural genes, a promoter, and an operator, with transcription regulated by repressors, activators, and small effector molecules.Structure and Function of OperonsAn operon is a cluster of structural genes transcribed together under the control of a single promoter. The promoter region...
Inducible Operons: lac Operon
The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside...

