バクテリアのRNAポリメラーゼホロ酵素の結晶構造は,解像度2.6Aで
Dmitry G Vassylyev1, Shun-ichi Sekine, Oleg Laptenko
1Cellular Signaling Laboratory, RIKEN Harima Institute at Spring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo, Hyogo 679-5148, Japan. dmitry@yumiyoshi.harima.riken.go.jp
Nature
|May 10, 2002
まとめ
細菌のRNAポリメラーゼホロ酵素の結晶構造を決定し,シグマ因子がどのように結合して転写を開始するかを明らかにしました. この構造的な洞察は,細菌における転写開始のメカニズムを明確にします.
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:
- 細菌の転写を開始するには,コア酵素とシグマ因子によって形成されるRNAポリメラーゼホロ酵素が必要です.
- シグマ因子の役割を理解することは,転写調節の解明に不可欠です.
研究 の 目的:
- 細菌のRNAポリメラーゼホロ酵素の高解像度結晶構造を決定する.
- 転写開始のメカニズムに関する構造的な洞察を提供するために.
主な方法:
- X線結晶グラフィーです.
- 2.6 A解像度でのタンパク質構造の決定
主要な成果:
- Thermus thermophilus RNAポリメラーゼホロ酵素の結晶構造が決定されました.
- シグマサブユニットのドメインは,RNAポリメラーゼコアに対して特定の位置をとり,DNA結合とRNA脱出チャネルに影響を与えます.
- 拡張されたリンカードメインは,シグマのN端とC端のドメインを接続し,アクティブサイトとRNA出口チャネルを通過します.
結論:
- ホロ酵素構造は,重要な機能領域の空間的組織を明らかにします.
- 転写中間複合体と開始メカニズムを理解するための構造的基礎を提供します.
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...
Transcription 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...
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...
Nucleic Acid Structure
The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA has a double-helix structure. The...
DNA Structure
DNA has a double-helix structure. The...


