促进RNA聚合酶III的循环回收途径
1Service de Biochimie et Génétique Moléculaire Commissariat à l'Energie Atomique-Saclay, Gif-sur-Yvette, France.
Cell
|January 26, 1996
概括
酵母RNA聚合酶III (pol III) 通过快速循环实现高转录效率,而不仅仅是启动. 这种聚合酶在同一个基因上迅速重新启动,这表明从终结部到促进部的直接转移模式.
科学领域:
- 分子生物学分子生物学
- 生物化学 生化学
- 遗传学 是一个遗传学.
背景情况:
- RNA聚合酶III (pol III) 对于转录小RNAs至关重要.
- 了解pol III在体外转录高效率背后的机制是关键.
研究的目的:
- 阐明驱动酵母RNA聚合酶III的高体外转录效率的主要机制.
- 研究RNA聚合酶III回收和重新启动的动力学和要求.
主要方法:
- 对RNA聚合酶III转录的动态分析.
- 模板竞争分析. 模板竞争分析.
- 肝素耐药性测试用于评估聚合酶释放.
主要成果:
- 在预组装的转录复合体上RNA聚合酶III的循环循环比最初的转录周期要快得多.
- 有效的回收需要在自然信号上终止,并且受到高UTP度的青;流水转录阻碍了回收.
- 重新启动表现出对肝素的抗性增加,表明聚合酶在终止后可能不会完全释放.
- 模板竞争试验表明RNA聚合酶III承诺在同一基因上重新启动.
结论:
- 酵母RNA聚合酶III的高体外效率主要归因于聚合酶的快速循环.
- 一个模型建议RNA聚合酶从终结点直接转移到促进器位点,这一发现得到了支持.
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...
Eukaryotic RNA Polymerases
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
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...
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...
Eukaryotic RNA Polymerases
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...


