相关实验视频
Updated: Jul 11, 2026

07:44
High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
一个由RNA组成的III类转录因子
L S Young1, H M Dunstan, P R Witte
1Institute of Molecular Biology, University of Oregon, Eugene 97403.
概括
一种新的RNA组件TFIIIR对于丝虫RNA聚合酶III的转录至关重要. 这一发现挑战了转录机制仅以蛋白质为基础的假设,揭示了基因表达中的关键非多类因素.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 基因转录通常被理解为涉及基于蛋白质的机械.
- RNA聚合酶III是转录特定基因的关键酶.
研究的目的:
- 通过丝虫RNA聚合酶III进行体外转录所需的组件的研究.
- 识别和描述涉及这一过程的新型转录因子.
主要方法:
- 使用丝虫RNA聚合酶III的体外转录试验.
- 转录因子的生物化学表征,包括对各种治疗方法 (热,洗剂,酶) 的敏感性.
主要成果:
- 鉴定出一种转录因子TFIIIR,它对RNA聚合酶III活性至关重要.
- TFIIIR不是多,但似乎是由RNA组成的.
- TFIIIR显示耐热,洗剂,,蛋白酶和DNase,但对和RNase敏感.
结论:
- 基因转录机制不仅仅由多质组成.
- RNA可以作为RNA聚合酶III的关键非多转录因子 (TFIIIR) 发挥作用.
- TFIIIR代表了一个独特的转录组件类别.
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...
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...
General Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
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...

