関連する実験動画
Updated: May 7, 2026
07:27
Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
Published on: April 30, 2010
複製性ヘックスアメリカンヘリケーズにおけるDNA転位のメカニズム
Eric J Enemark1, Leemor Joshua-Tor
1W. M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724, USA.
Nature
|July 21, 2006
まとめ
パピローマウイルスE1ヘリケーズは,DNA転位のためのユニークな階段メカニズムを使用しています. ATPの水解は,サブユニットの連続的な動きを駆動し,単一鎖のDNAを六合体環を通して転位させます.
科学分野:
- 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
- 分子ウイルス学 分子ウイルス学
背景:
- パピローマウイルスE1タンパク質は,ヘクサメリクリングヘリケーズとして機能する.
- AAA+ファミリータンパク質E1は,ウイルスのDNA複製に不可欠です.
- E1によるATP依存DNA転位のメカニズムは,まだ完全に理解されていません.
研究 の 目的:
- パピローマウイルスE1ヘリカーゼによるATP水解と結合したDNA転位のメカニズムを解明する.
- E1ヘクサマーの核酸依存型構造変化の構造的基礎を決定する.
主な方法:
- X線結晶学を用いて,E1ヘクサマーの高解像度構造を取得した.
- 構造は,単一鎖のDNAと様々なヌクレオチド状態 (ATP,ADP,Apo) を含む複合体で決定されました.
主要な成果:
- 結晶構造は,ヘクサマーチャネルに結合した単一DNA鎖を明らかにしています.
- DNAを結合するヘアピンが渦巻きの階段を形成し, DNAの脊髄と連続的に相互作用します.
- E1サブユニットの特徴的な構造構造は,ATP,ADP,アポ状態と相関しており,ヘアピンの高さに関連しています.
結論:
- 配列的なATP水解とE1サブユニットの構成変化によって駆動される段階的なDNA転位機構が提案されています.
- 各サブユニットはATPサイクルを進み,DNAを結合するヘアピンを階段から下ろしてDNAを転位させる.
- ヘクサメリカリングの周りのこの協調的な作用は,効率的な単一鎖DNAの動きを促進します.
関連する概念動画
01:02The DNA Replication Fork
An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in...
00:55DNA Helicases
DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...
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...
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
01:02The DNA Replication Fork
An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in...
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...