核酸辅因子对大肠杆菌Rep基酶-DNA结合的Allosteric作用
1Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110.
概括
大肠杆菌的Rep螺旋酶在DNA结合时变质,核酸辅因子影响DNA相互作用. 这种机制对于DNA复制和解至关重要.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 在复制过程中,大肠杆菌Rep旋酶对于解复杂DNA至关重要.
- 功能性酶是一个二聚体,在DNA结合后形成,每个原聚体能够结合单链或双链DNA.
研究的目的:
- 量化研究DNA结合和DNA诱导的Rep二元化过程中的能量.
- 调查核酸辅因子,腺二酸盐 (ADP) 和腺三酸盐 (ATP) 模拟AMPP (NH) P对这些过程的影响.
主要方法:
- 对DNA结合和Rep二元化的定量分析.
- 使用ADP和不可水解的ATP模拟AMPP (NH) P作为核酸辅因子.
主要成果:
- 核酸辅因子对Rep酶DNA结合具有显著的全效应.
- ADP结合促进了Rep二极体,其中两种质体结合了单链DNA.
- AMPP(NH) P结合有利于Rep二元,它们同时结合单链和双链DNA.
结论:
- 提出了一种由二维Rep酶解的DNA滚动模型.
- 酶转位与ATP结合相结合,而ATP水解则驱动每个催化周期的多个DNA基对的解.
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