Historically, small molecules biosynthesised by bacteria have been an excellent source for antibacterial drugs. Today, however, the rediscovery of known compounds is a significant hurdle to developing new antimicrobials. Here we use a genome mining and synthetic biology approach to discover the ambocidins: calcium‐dependent lipodepsipeptides that are active against drug‐resistant Gram‐positive pathogens. By cloning a silent biosynthetic gene cluster (the amb cluster) from Streptomyces ambofaciens ATCC 2387 and integrating this into the chromosome of Streptomyces avermitilis we induce expression of ambocidin A and B: two new Nε‐hydroxyarginine‐containing cyclic lipodepsipeptides active against drug‐resistant Gram‐positive pathogens. Using a panel of Streptomyces host strains, we show that the choice of heterologous host is critical for producing the biologically active compounds, and that inappropriate host choice leads to aberrant production inactive derivatives. We show that Nε‐hydroxyarginine is the product of a haem‐dependent oxygenase and that it enhances biological activity. Ambocidin A inhibits cell wall biosynthesis by binding to Lipid II at a different site than vancomycin. Unlike daptomycin, ambocidin A retains antimicrobial activity in the presence of lung‐surfactant, giving it the potential to treat bacterial pneumonia. Our work expands the family of calcium‐dependent lipopeptide antibiotics with new members exhibiting a distinct mechanism of action.

中文翻译：

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通过克隆生物合成基因簇的宿主依赖性异源表达发现针对耐药病原体的钙依赖性脂肽抗生素


从历史上看，细菌生物合成的小分子一直是抗菌药物的极好来源。然而，如今，已知化合物的重新发现成为开发新抗菌药物的重大障碍。在这里，我们使用基因组挖掘和合成生物学方法来发现 ambocidins：钙依赖性脂缩肽，对耐药革兰氏阳性病原体具有活性。通过克隆来自安博链霉菌 ATCC 2387 的沉默生物合成基因簇（amb 簇）并将其整合到阿维链霉菌的染色体中，我们诱导了安博西丁 A 和 B 的表达：两种新的含 Nε-羟基精氨酸的环状脂缩肽，对耐药革兰氏菌有活性‐阳性病原体。使用一组链霉菌宿主菌株，我们表明异源宿主的选择对于产生生物活性化合物至关重要，并且不适当的宿主选择会导致异常产生无活性衍生物。我们证明 Nε-羟基精氨酸是血红素依赖性加氧酶的产物，并且它可以增强生物活性。安博西丁 A 通过在与万古霉素不同的位点结合脂质 II 来抑制细胞壁生物合成。与达托霉素不同，安博西丁 A 在肺表面活性剂存在下仍保留抗菌活性，使其具有治疗细菌性肺炎的潜力。我们的工作扩大了钙依赖性脂肽抗生素家族，新成员表现出独特的作用机制。