产品的形成由Promiscuous Lanthipeptide 合成酶 ProcM 在动力控制下进行
Yi Yu1, Subha Mukherjee1, Wilfred A van der Donk1
1†Department of Biochemistry, ‡Department of Chemistry, and §Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave. Urbana, Illinois 61801, United States.
Journal of the American Chemical Society
|March 25, 2015
概括
兰氏合成酶ProcM表现出高产品选择性,突变影响循环化速率和区域选择性. 最初的环形形成决定了最终产品的拓,而不是热力学控制.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 自然产品 化学 化学
背景情况:
- 兰氏是一种具有多种生物活性的核糖体合成和翻译后修饰 (RiPPs).
- 关键的结构特征包括氨酸 (Lan) 或甲基氨酸 (MeLan) 桥梁.
- 兰氏合成酶ProcM表现出广泛的基质耐受性,但具有很高的产品选择性.
研究的目的:
- 通过ProcM.研究兰氏合成中的区域选择性机制.
- 确定活性部位残留物和初始循环事件在产品形成中的作用.
- 探索突变对循环化速率和产品拓学的影响.
主要方法:
- 在ProcM活性位点残留物 (联体) 的位点定向突变发生.
- 使用特定的兰西基质 (ProcA1.1,ProcA2.8,ProcA3.3) 分析循环化速率和产品形成.
- 反应产品的表征,以评估区域选择性和环形拓.
主要成果:
- 活点联体的突变降低了循环化速率,特别是在第二个循环化阶段.
- 特定突变改变了基质ProcA3.3的循环化区域选择性,产生了一种新的主要产物.
- ProcM无法纠正错误循环的中间体,表明缺乏热力学控制.
结论:
- 通过ProcM形成兰氏的高区域选择性主要取决于初始环形形成的选择性.
- 影响活性部位的突变影响反应动力学和产品特异性.
- 兰氏生物合成是动态控制的,早期的循环事件指导着整体产品结构.
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