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Updated: Jul 14, 2026
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TFIIB-およびIIE-RNAポリメラーゼII複合体の二次元結晶学:開始部位選択と初期複合体の形成への影響
K K Leuther1, D A Bushnell, R D Kornberg
1Department of Structural Biology, Stanford University School of Medicine, California 94305-5400, USA.
Cell
|May 31, 1996
まとめ
電子結晶学により,RNAポリメラーゼIIに結合する転写因子IIB (TFIIB) とIIE (TFIIE) が検出されました. これらの発見は,TFIIBがDNAの位置を定着させ,TFIIEが転写開始時に構造変化を促進することを示唆しています.
科学分野:
- 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
- バイオケミストリー バイオケミストリー
背景:
- トランスクリプションの開始は,様々なタンパク質因子によって規制される複雑なプロセスです.
- RNAポリメラーゼIIとの転写因子の相互作用の構造的基礎を理解することは,遺伝子調節を解読する上で極めて重要です.
研究 の 目的:
- 転写因子IIB (TFIIB) とIIE (TFIIE) の転写開始における構造的役割を明らかにする.
- TFIIBとTFIIEのRNAポリメラーゼIIへの結合を高解像度電子結晶学を用いて視覚化する.
主な方法:
- 電子結晶学を用いて,TFIIBとTFIIEに結合するRNAポリメラーゼIIの構造を決定した.
- この研究は15.7 Åの解像度を達成し,複合体のプロジェクション画像を提供した.
主要な成果:
- TFIIBとTFIIEをRNAポリメラーゼIIとの複合体で直接可視化する.
- 構造データは,これらの転写因子のポリメラーゼに対する空間的配置を明らかにした.
結論:
- TFIIBは,ポリメラーゼ活性センターから特定の距離にTATA結合DNA要素を配置して,転写開始部位を定義する機能を持つ可能性があります.
- TFIIEは,トランスクリプション開始時にポリメラーゼ-DNA相互作用により,活性部位における重要な形状の変化に役割を果たしていると考えられています.
関連する概念動画
01:23RNA Structure
Overview
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a...
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a...
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...
02:33Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
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...
01:19RNA Structure
The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...
01:30General 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...