転写の構造的基礎は,3.3 A解像度のRNAポリメラーゼII延長複合体である
1Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA.
まとめ
転写中のRNAポリメラーゼIIの結晶構造は,DNAがどのように解き放たれ,RNAとハイブリッドを形成するかを明らかにします. この構造は,RNA合成と転位の重要な側面を説明します.
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:
- RNAポリメラーゼIIは,DNAをRNAに転写し,遺伝子発現に不可欠です.
- 転写中のその構造を理解することは,遺伝子調節を解読する鍵です.
- 以前のモデルでは,トランスクリビング複合体の原子レベルの詳細が欠けていました.
研究 の 目的:
- 転写中のRNAポリメラーゼIIの高解像度結晶構造を決定する.
- DNA,RNA,および酵素の活性部位の相互作用を視覚化するために.
- 転写ダイナミクスの構造的基礎を解明する.
主な方法:
- X線結晶グラフィーです.
- 3.3 Å 解像度構造の決定
- タンパク質と核酸の相互作用の分析
主要な成果:
- 転写中のRNAポリメラーゼIIの詳細な構造.
- DNA解き放たれとDNA-RNAハイブリッド形成の可視化.
- クランプの閉塞とスイッチ領域の順序付け,ハイブリッド結合部位の作成など,構造変化の特定.
- 転写メカニズムを説明するタンパク質-核酸接触のマッピング.
結論:
- 決定された構造は,トランスクリプションの延長に関する原子的な洞察を提供します.
- 構造的特徴は,DNA/RNA鎖の分離とRNA合成の特異性を説明する.
- この発見は,不運なサイクルと転位プロセスに光を当てています.
関連する概念動画
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...
Transfer RNA Synthesis
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
RNA-seq
RNA sequencing, or RNA-Seq, is a high-throughput sequencing technology used to study the transcriptome of a cell. Transcriptomics helps to interpret the functional elements of a genome and identify the molecular constituents of an organism. Additionally, it also helps in understanding the development of an organism and the occurrence of diseases.
Before the discovery of RNA-seq, microarray-based methods and Sanger sequencing were used for transcriptome analysis. However, while microarray-based...
Before the discovery of RNA-seq, microarray-based methods and Sanger sequencing were used for transcriptome analysis. However, while microarray-based...
RNA 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...


