One, Two, and Three Rieske Routes for Catalyzing Site-Specific Oxygenations

摘要 Rieske加氧酶利用过渡金属的反应性来执行强大的、高效的和定位的 传统惰性键的转变。这些酶将[2Fe-2S]簇与非血红素偶联 铁的位置，利用分子氧(O2)作为生物合成和降解途径中的共同底物。在这些 在反应中，O2的动力学稳定性通过使用非血红素铁中心来克服，它与O2和 通过形成活性氧中间体促进其裂解。这种活性物种被用来 从衬底中提取一个氢原子，并引发一系列具有挑战性的转变。里斯克 加氧酶的功能已知为双加氧酶或单加氧酶，甚至已被证明催化 顺序单氧化反应。正如在许多生物合成途径中所展示的那样 具有抗生素、抗真菌、抗癌或麻醉活性的天然产物，以及在 降解环境污染物，这些酶在区分这两种酶时表现出精妙的控制 反应类型，以确保仅催化预期的转化。因此，这些酶代表一种 工业生产药品和日用化学品的酶策略的宝贵来源，或 促进生物修复工作。然而，关于这些是如何实现的，我们严重缺乏相关信息。 酶能够使用一组共同的金属分配中心来催化不同部位的特定反应 结果。因此，在这项工作中，我们将揭示大自然用来调整 Rieske加氧酶的选择性和催化性能。这一知识将提供预测性 重新调整Rieske加氧酶的用途以催化定制反应的力量，并将支持开发 他们为各种各样的生物技术努力提供的化学物质。

Abstract Rieske oxygenases harness the reactivity of transition metals to perform powerful, efficient, and site-specific transformations of traditionally inert bonds. These enzymes, which couple a [2Fe-2S] cluster with a non-heme iron site, exploit molecular oxygen (O2) as a co-substrate in biosynthetic and degradative pathways. In these reactions, the kinetic stability of O2 is overcome by the use of the non-heme iron site, which binds O2 and promotes its cleavage via the formation of an activated oxygen intermediate. This reactive species is used to abstract a hydrogen atom from a substrate and initiate an array of challenging transformations. Rieske oxygenases are known to function as dioxygenases or monooxygenases, and have even been shown to catalyze sequential monooxygenation reactions. As demonstrated in a number of biosynthetic pathways that produce natural products with antibiotic, antifungal, anticancer, or anesthetic activities, as well as in pathways that degrade environmental pollutants, these enzymes demonstrate exquisite control in differentiating between these reaction types to ensure that only the intended transformation is catalyzed. Thus, these enzymes represent a valuable source of enzymatic strategies to industrially produce pharmaceuticals and commodity chemicals, or facilitate bioremediation efforts. However, there is a critical lack of information available about how these enzymes are able to use a common set of metallocenters to catalyze site-specific reactions with diverse outcomes. Therefore, in this work, we will uncover the architectural strategies that Nature uses to tune the selectivity and catalytic repertoire of the Rieske oxygenase enzymes. This knowledge will provide predictive power towards repurposing Rieske oxygenases to catalyze custom reactions, and will support efforts to exploit their chemistry for a wide variety of biotechnological endeavors.