サブストラット結合は,ヒトDNAプライマスのレドックスシグナリングを調節する
Elizabeth O'Brien1, Marilyn E Holt2, Lauren E Salay2
1Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States.
Journal of the American Chemical Society
|November 16, 2018
まとめ
DNAプリマースは,DNA複製中のシグナル伝達のために [4Fe4S]クラスタを使用する. DNAとNTPを結合すると,酵素活性が増加します.
科学分野:
- 生物化学
- 分子生物学
- 酵素学
背景:
- DNA複製には,RNAプライマーを合成するDNAプライマースが必要です.
- プリマゼは,異なる機能ドメインを持つヘテロディマー (p48/p58) である.
- p58の [4Fe4S] クラスターは酵素活性に不可欠です.
研究 の 目的:
- 無傷なDNAプリマースヘテロダイマーにおける [4Fe4S]クラスタの酸化還元変異特性について調査する.
- DNAとNTPの結合が クラスタの電気化学信号にどのように影響するか理解する.
- リドックス特性とプリマースの触媒活動との関係を調べる.
主な方法:
- 完全なp48/p58プリマースヘテロダイマーを研究するためにDNA電気化学が採用されました.
- [4Fe4S]クラスタの酸化還元力を分析するために,電気化学的測定を行った.
- 酵素活性アッセイは,NTP結合が触媒に与える影響を評価するために実施された.
主要な成果:
- [4Fe4S]クラスタの強固な酸化還元信号は,DNAとNTPの両方の同時結合を必要とした.
- NTP結合により,クラスタの酸化還元電位は生理学的な範囲 (~160 mV vs NHE) に変化した.
- NTPsでプリマースをプリロードすると,触媒活性が強化され,より活発な形状を示します.
結論:
- サブストラット結合 (DNAとNTP) と構成の変化は,4Fe4S]クラスタの酸化還元信号を調節する.
- 静電相互作用とサブユニットの配列はクラスタの環境とシグナリングに影響します.
- これらの発見は,4Fe4S]クラスタを持つ多サブユニットDNA処理酵素のシグナル伝達に関する理解に重要である.
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