Divergence of Carboxylate-Bridged Diiron Enzymes for Natural Product Biosynthesis

双核铁酶(DIS)利用一种羧酸和组氨酸协调的辅因子来影响 具有人工挑战性的生化反应。DIS的公认角色最近得到了 扩展到包括几个重要的天然产物生物合成途径，包括 病原菌中叶酸的产生，卤素对抗生素效力的调节 装置，以及通过碳-碳键合成必需的次生代谢物 分裂。为了理解一个非常相似的辅因子和结构核心的分子基础 可以执行如此不同的功能，我们建议研究三个新发现的包含 几乎相同的配位基元和整体结构支架，但协调化学在 从根本上既不同于彼此，也不同于经过充分研究的方式，而是 对底物进行氧化。拟议的工作将利用一系列光谱， 动力学和遗传工具，以确定蛋白质、底物和辅因子的关键位置，从而使 这种截然不同的活动。DI函数重编程的结构基础的阐明 将为合成新的药效团和分子提供生化模板 为微生物增殖和致病的关键途径奠定基础。

Dinuclear iron enzymes (DIs) utilize a carboxylate- and histidine-coordinated cofactor to affect synthetically challenging biochemical reactions. The recognized roles for DIs have recently expanded to include several important natural product biosynthetic pathways, including the generation of folate in pathogenic bacteria, the modulation of antibiotic potency via halogen installation, and the synthesis of essential secondary metabolites through carbon-carbon bond scission. To understand the molecular basis for how a very similar cofactor and structural core can perform such diverse functions, we propose to study three newly discovered DIs that contain nearly identical coordination motifs and overall structural scaffolds, but orchestrate chemistry in ways that fundamentally differ from both each other and from well-studied DIs that instead perform the oxygenation of substrates. The proposed work will utilize an array of spectroscopic, kinetic, and genetic tools to identify key sites of the protein, substrate, and cofactor that enable such disparate activities. An elucidation of the structural basis for DI functional reprogramming will provide a biochemical template for the synthesis of new pharmacophores and the molecular basis for pathways that are critical for microbial proliferation and pathogenicity.