分子スロットル:再結合ホットスポット・チは,RecBCDヘリアースによるDNA転位を制御する

Maria Spies¹, Piero R Bianco, Mark S Dillingham

¹Section of Microbiology, Center for Genetics and Development, University of California, Davis 9561, USA.

Cell

|September 19, 2003

まとめ

DNA修復に不可欠なRecBCD酵素は,チ配列で一時停止する. この相互作用により,DNAの転位速度が半減し,モーターサブユニットの解離が示唆される.

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
遺伝学遺伝学とは

背景:

RecBCD酵素は,DNAの断裂時に同類の再結合を開始する重要なヘリケーズ / ヌクレアーズです.
DNA配列のチは,RecBCD酵素の核酵素活性とRecAの負荷を調節する.
Chi認識は,RecBCD酵素とDNAの相互作用に影響する.

研究の目的:

RecBCD酵素の転位ダイナミクスに対するチ配列の効果を調査する.
チがRecBCD酵素活性に影響を与えるメカニズムを解明する.

主な方法:

単一分子DNA転位アッセイは,個々のRecBCD酵素の動きを観察するために使用されました.
DNA分子に沿ったRecBCD酵素の転位をリアルタイムで観察する.

主要な成果:

RecBCD酵素は,Chi DNA配列で正確に一時停止することが観察されました.
チでの一時停止の後,RecBCD酵素の転位速度は初期速度の約50%低下した.
これは,チ相互作用によって酵素の運動機能の変化を示唆している.

結論:

チ配列は,RecBCD酵素の転位を調節し,大幅な一時停止およびその後の速度低下を引き起こします.
この調節は,モーターサブユニット (おそらく RecD) がホロ酵素から分離した結果として生じると考えられています.
このメカニズムは,DNA修復と再結合の開始の調節に関する新しい洞察を提供します.

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