哺乳類のrDNA複製の終止:転写終止因子TTF-Iによる複製フォークの運動の極性停止

J K Gerber¹, E Gögel, C Berger

¹Institute of Biochemistry, University of Würzburg, Germany.

Cell

|August 8, 1997

まとめ

リボソームDNA内の複製フォークバリア (RFB) は,DNA複製と転写の衝突を防ぐ. 終結因子TTF-IはRFBの活動に不可欠であり,複製が転写と同じ方向に進んでいることを保証します.

科学分野:

分子生物学は分子生物学である.
遺伝学遺伝学とは
DNAレプリケーション DNA複製

背景:

ユーカリオットのリボソームRNA遺伝子は,3'端に複製フォークバリア (RFB) を持っています.
このRFBはDNA複製を単方向の進行に制限し,転写方向と整列させます.

研究の目的:

RFBのメカニズムと要件を in vitroで調査する.
RFB活動における転写終止因子の役割を決定する.

主な方法:

ネズミのrDNAを含むDNA構造と,HeLa細胞抽出物におけるSV40起源の複製.
サル・ボックス・ターミネーターと側面配列の変異分析.
TTF-Iの枯渇とRFB活動の分析.

主要な成果:

RFBは試験管内で成功裏に再現され,その極性性とモジュール組織性を実証しました.
サル・ボックス・ターミネーターと特定の側面のシーケンスの両方がRFBの機能に不可欠です.
ターミネーターの変異またはTTF-Iの欠如はRFB活動を廃止しました.

結論:

複製フォークバリアを確立するために,転写終止因子TF-Iは不可欠です.
TTF-Iは,RFBを媒介することによって,DNA複製と転写機構の間の正面衝突を防止します.
このメカニズムは,リボソームRNA遺伝子におけるDNA複製と転写の調整を保証する.

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