関連する実験動画
Updated: May 29, 2026
09:33
Rapid Isolation of the Mitoribosome from HEK Cells
Published on: October 4, 2018
人間のミトコンドリアRNAポリメラーゼの構造
Rieke Ringel1, Marina Sologub, Yaroslav I Morozov
1Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
Nature
|September 28, 2011
まとめ
ミトコンドリアRNAポリメラーゼ (mtRNAP) は,トランスクリプションの開始のためにTFAMとTFB2Mを必要とします. X線構造はmtRNAPPを明らかにしています.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
背景:
- ミトコンドリアの転写は,単一のサブユニットRNAポリメラーゼ (mtRNAP) に依存しています.
- mtRNAPは,バクテリオファージT7RNAポリメラーゼとの遠い祖先を共有しています.
- T7RNAPとは異なり,mtRNAPはプロモーター結合とDNA溶解のために転写因子TFAMとTFB2Mを必要とします.
研究 の 目的:
- 人間のmtRNAP機能の構造的基礎を解明する.
- ミトコンドリアの転写開始におけるTFAMとTFB2Mの役割を理解する.
- mtRNAP.の進化に関する洞察を提供するためです.
主な方法:
- 2.5 Åの解像度でヒトmtRNAPのX線結晶学.
- 機能ドメインを調査するためのサイト指向型変異.
- トランスクリプションアッセイの分析.
主要な成果:
- 構造は,T7のような触媒ドメイン,新しいペンタトリコペプチドの繰り返しドメイン,そして指の位置変更ドメインを明らかにします.
- ペンタトリコペプチドリピートドメインはDNA結合ループを隔離し,プロモーター結合におけるTFAMの役割を説明する.
- 再配置されたドメインは,TFB2Mのプロモーター・メルトングの必要性を説明する.
結論:
- この構造は,mtRNAPが,固有のプロモーター結合と融解能力を失ってしまったことを説明する.
- TFAMとTFB2Mの進化的獲得は,ミトコンドリアの遺伝子調節を可能にしました.
- これらの発見は,ミトコンドリアの転写メカニズムを研究するための新しい道を開きます.
関連する概念動画
00:58Eukaryotic 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...
00:58Eukaryotic 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...
01:47Transcription 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...
00:43Bacterial 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...
00:43Bacterial 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...
03:01The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...