Nonribosomal peptides (NRP) are crucial molecular mediators in microbial ecology and provide indispensable drugs. Nevertheless, the evolution of the flexible biosynthetic machineries that correlates with the stunning structural diversity of NRPs is poorly understood. Here, we show, that recombination is a key driver in the evolution of bacterial NRP synthetase (NRPS) genes across distant bacterial phyla that has guided structural diversification in a plethora of NRP families by extensive mixing and matching of biosynthesis genes. The systematic dissection of a large number of individual recombination events did not only unveil a striking plurality in the nature and origin of the exchange units but allowed the deduction of overarching principles that enable the efficient exchange of adenylation (A) domain substrates whilst keeping the functionality of the dynamic multienzyme complexes. In the majority of cases, recombination events have targeted variable portions of the A_core domains, yet domain interfaces and the flexible A_sub domain remained untapped. Our results strongly contradict the widespread assumption that adenylation and condensation (C) domains coevolve and significantly challenge the attributed role of C domains as stringent selectivity filter during NRP synthesis. Moreover, they teach valuable lessons on the choice of natural exchange units in the evolution of NRPS diversity, which may guide future engineering approaches.

中文翻译：

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创造非核糖体肽多样性的重组事件景观


非核糖体肽（NRP）是微生物生态学中至关重要的分子介质，并提供不可或缺的药物。然而，人们对与 NRP 惊人的结构多样性相关的灵活生物合成机制的进化知之甚少。在这里，我们表明，重组是细菌 NRP 合成酶 (NRPS) 基因跨远距离细菌门进化的关键驱动因素，通过生物合成基因的广泛混合和匹配，指导了大量 NRP 家族的结构多样化。对大量单个重组事件的系统剖析不仅揭示了交换单元的性质和起源的惊人多样性，而且还可以推论出能够实现腺苷酸化（A）结构域底物的有效交换同时保持功能性的总体原理动态多酶复合物。在大多数情况下，重组事件以 A_核心结构域的可变部分为目标，但结构域接口和灵活的 A_子结构域仍未开发。我们的结果强烈反驳了普遍的假设，即腺苷酸化和缩合（C）结构域共同进化，并显着挑战了 C 结构域在 NRP 合成过程中作为严格选择性过滤器的归因作用。此外，他们就 NRPS 多样性演化中自然交换单元的选择提供了宝贵的经验教训，这可能会指导未来的工程方法。