Using an established CRISPR-Cas mediated genome editing technique for streptomycetes, we explored the combinatorial biosynthesis potential of the auroramycin biosynthetic gene cluster in Streptomyces roseosporous. Auroramycin is a potent anti-MRSA polyene macrolactam. In addition, auroramycin has antifungal activities, which is unique among structurally similar polyene macrolactams, such as incednine and silvalactam. In this work, we employed different engineering strategies to target glycosylation and acylation biosynthetic machineries within its recently elucidated biosynthetic pathway. Auroramycin analogs with variations in C-, N- methylation, hydroxylation and extender units incorporation were produced and characterized. By comparing the bioactivity profiles of five of these analogs, we determined that unique disaccharide motif of auroramycin is essential for its antimicrobial bioactivity. We further demonstrated that C-methylation of the 3, 5-epi-lemonose unit, which is unique among structurally similar polyene macrolactams, is key to its antifungal activity.

中文翻译：

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抗真菌，抗MRSA金霉素的生物合成工程。

使用建立的链霉菌的CRISPR-Cas介导的基因组编辑技术，我们探索了玫瑰孢链霉菌中金霉素霉素生物合成基因簇的组合生物合成潜力。金霉素是一种有效的抗MRSA多烯大内酰胺。此外，金霉素具有抗真菌活性，这在结构相似的多烯大内酰胺类化合物中是独特的，例如茚来那定和西伐内酰胺。在这项工作中，我们采用了不同的工程策略，以在其最近阐明的生物合成途径内靶向糖基化和酰化生物合成机制。产生并表征了具有C-，N-甲基化，羟基化和扩展单元掺入变化的金霉素。通过比较其中五个类似物的生物活性，我们确定了金霉素的独特二糖基序对其抗菌生物活性至关重要。我们进一步证明，在结构上相似的多烯大内酰胺类中独特的3，5-表-柠檬糖单元的C-甲基化是其抗真菌活性的关键。