関連する実験動画
Updated: Jun 13, 2026
08:24
Visualization of Replisome Encounters with an Antigen Tagged Blocking Lesion
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複製因子Cによる増殖細胞核抗原のリング開かれた状態の認識は,真核細胞のクランプ負荷を促進する
John A Tainer1, J Andrew McCammon, Ivaylo Ivanov
1Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, MB4, La Jolla, California 92037, USA.
Journal of the American Chemical Society
|May 12, 2010
まとめ
複製因子C (RFC) は,増殖細胞核抗原 (PCNA) のスライディングクランプに結合し,その開いた形状を安定させます. この相互作用は,DNA複製と修復におけるクランプ・ロードサイクルに極めて重要です.
科学分野:
- 分子生物学は分子生物学である.
- 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
背景:
- 増殖細胞核抗原 (PCNA) は,DNA複製,改変,修復に不可欠な重要なスライディングクランプタンパク質です.
- PCNAは,その機能のためにプライマー・テンプレート・ジャンクションでレプリケーション・ファクターC (RFC) クランプ・ローダーによって開き,再密封されなければならない.
- RFC/PCNAの相互作用メカニズムを理解することは,プロセス性DNA複製の解明の鍵です.
研究 の 目的:
- クランプ・ロードプロセス中のRFC/PCNA複合体の構成変化を調査する.
- PCNAクランプの開閉のメカニズムにおけるRFCの役割を明らかにする.
- RFCの有無でPCNAコンフォーマーショントランジションの自由エネルギー環境を分析する.
主な方法:
- RFC/PCNA複合体の構造的再編成を研究するために生体物理学技術を活用した.
- RFC.と RFC.なしのPCNAクランプ開口の自由エネルギープロファイルの比較を行った.
- RFCとPCNAのオープンコンフォームの相互作用インターフェースを分析した.
主要な成果:
- RFCバインディングは,RFC/PCNA複合体における重要な構成的再配置を誘導し,拡張されたインターフェイスを作成します.
- RFCの5つのサブユニットすべてに結合した開いた状態のPCNAは,オープンコンフォーメーションに閉じ込められ,変換された自由エネルギー景観を経験します.
- RFCはPCNAの閉じた状態を不安定化しませんが,代わりに,選択的に開いた状態を安定化します.
結論:
- クランプ・ロードサイクルにおけるRFCの主な役割は,開いたPCNAコンフォームの選択的安定化である.
- 相互作用メカニズムは,DNAプロセスにおけるPCNAの役割を促進するRFCの機能を強調しています.
- この研究は,DNA複製の信頼性と効率を制御する分子機構に関する重要な洞察を提供します.
関連する概念動画
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...
02:38S-Cdk Initiates DNA Replication
The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
02:38S-Cdk Initiates DNA Replication
The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
02:37Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
02:39Positive Regulator Molecules
Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.
01:45Positive Regulator Molecules
To consistently produce healthy cells, the cell cycle—the process that generates daughter cells—must be precisely regulated.