基质捕获在多基酸合成酶和酸酶域中:巨乳素形成的结构基础
bioRxiv : the preprint server for biology
|July 1, 2024
概括
研究人员使用1,3-二氨基酸 (DAP) 来捕获中间体,设计了硫酶 (TEs),揭示了类抗生素支架的形成方式,并使生物催化剂的优化成为可能.
科学领域:
- 生物化学 生物化学
- 合成生物学 合成生物学
- 药物发现 药物发现 药物发现
背景情况:
- 抗生素耐药性需要新的抗菌药物,特别是宏类药物.
- 聚基酸合成酶 (PKS) 化酶 (TEs) 催化巨乳素的形成,这对宏类抗生素至关重要.
- 对 TE 机制的有限理解阻碍了对各种基质的生物催化剂的开发.
研究的目的:
- 阐明TE基质选择性在巨乳素形成中的机制.
- 为更广泛的自然和非自然基质设计TEs作为生物催化剂.
- 为了了解TEs如何直接对核友性攻击进行麦克罗拉克环闭合.
主要方法:
- 通过用1,3-diaminopropionic acid (DAP) 取代活性位点氨酸氧化物,将乙烯酸酶中间体作为稳定胺基被捕获.
- 从皮克罗米辛和红色素途径中净化了DAP修饰的TE (DAPTE).
- 测试了TEDAP变体与各种多基酸中间体,并确定了晶体结构.
主要成果:
- 红素TE表现出允许的基质选择性,而皮克罗米辛TE对其本土基质具有选择性.
- 皮克罗米辛TEDAP的晶体结构揭示了一个卷曲的肝基质,其形状与活性部位高度互补.
- 在不同的TEs中观察到明显的乙腔形状,包括来自juvenimicin,tylosin和fluvirucin生物合成的TE.
结论:
- 根据活性位点架构,特别是乙腔,TEs表现出不同的基质选择性.
- 与DAP一起的工程测试提供了对基质结合和催化机制的见解.
- 了解 TE 的结构多样性有助于设计用于宏化物合成的新型生物催化剂.
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