関連する実験動画
Updated: Jul 21, 2026

07:44
High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
RNAポリメラーゼαサブユニットのドメイン組織:C末端の85種類のアミノ酸は,二分化とDNA結合を可能にするドメインを形成する
1Department of Chemistry, Rutgers University, New Brunswick, New Jersey 08855.
Cell
|September 9, 1994
まとめ
Escherichia coliのRNAポリメラーゼアルファサブユニットである.
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
- 構造生物学 構造生物学とは
背景:
- Escherichia coliのRNAポリメラーゼアルファサブユニットは,転写の開始に不可欠です.
- その構造と機能を理解することは,遺伝子調節機構の解読の鍵です.
研究 の 目的:
- E. coli RNAポリメラーゼアルファサブユニットの構造領域を区切る.
- C端末ドメイン (アルファCTD-2) の構造とDNA結合活性を特徴づける.
主な方法:
- ドメインを特定するための限られたタンパク質分解.
- アルファCTD-2断片の構造分析.
- 配列特異性を評価するためのDNA結合測定法.
主要な成果:
- アルファサブユニットは,N端末ドメイン,C端末ドメイン (alpha CTD-2),および柔軟なリンク器で構成されています.
- アルファCTD-2は,定義された二次構造 (40%アルファヘリックス) を有し,二重体として存在する.
- アルファCTD-2は配列特異的なDNA結合活性を示しています.
結論:
- E. coliのRNAポリメラーゼアルファ亜単体のC端末ドメインは,構造的で二重であり,DNAを特異的に結合します.
- これらの発見は,アップストリーム要素による転写活性化におけるアルファサブユニット関与のモデルを支持する.
関連する概念動画
Conservation of Protein Domains Over Different Proteins
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
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...
Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
Eukaryotic Transcription Activators
Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD.
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
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...

