関連する実験動画
Updated: Jul 11, 2026

07:44
High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
RNAから成るIII級転写因子
L S Young1, H M Dunstan, P R Witte
1Institute of Molecular Biology, University of Oregon, Eugene 97403.
まとめ
新しいRNA成分であるTFIIIRは,のRNAポリメラーゼIIIの転写に不可欠である. この発見は,転写機構はタンパク質のみに基づいているという仮定に異議を唱え,遺伝子発現における重要な非ポリペプチド因子を明らかにしています.
科学分野:
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
- 遺伝学 遺伝学とは
背景:
- 遺伝子転写は,通常,タンパク質ベースの機械を含むことを理解しています.
- RNAポリメラーゼIIIは,特定の遺伝子を転写する重要な酵素です.
研究 の 目的:
- シルクワームのRNAポリメラーゼIIIによってin vitroトランスクリプションに必要な成分を調査する.
- このプロセスに関与する新しい転写因子を特定し,特徴づけること.
主な方法:
- シルクワームのRNAポリメラーゼIIIを用いたインビトロ転写アッセイ.
- トランスクリプション因子の生化学的特徴,様々な処理 (熱,洗剤,酵素) に対する感受性を含む.
主要な成果:
- RNAポリメラーゼIII活性に不可欠な転写因子であるTFIIIRが特定されました.
- TFIIIRはポリペプチドではなく,RNAで構成されているようです.
- TFIIIRは,熱,洗剤,フェノール,プロテアゼ,DNaseに対する耐性を示したが,アルカリおよびRNaseに対する感受性を示した.
結論:
- 遺伝子転写機構は,ポリペプチドのみで構成されているわけではありません.
- RNAは,RNAポリメラーゼIIIの重要な非ポリペプチド転写因子 (TFIIIR) として機能することができます.
- TFIIIRは,トランスクリプションコンポーネントの異なるクラスを表しています.
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...
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...

