Self-immunity guided identification of threonyl-tRNA synthetase as the molecular target of obafluorin, a ß -lactone antibiotic
Self-immunity guided identification of threonyl-tRNA synthetase as the molecular target of obafluorin, a ß -lactone antibiotic
复制标题
自我免疫引导识别苏氨酰-tRNA合成酶作为奥巴氟林（一种β-内酯抗生素）的分子靶标
DOI：
10.1101/704981
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Scott T
中科院分区：
文献类型：
--
作者：
Scott T
为了满足抗生素发现不断增长的需求，迫切需要新的化学物质和抗生素靶标。许多以前被废弃的强效天然产物抗生素也可以提供先导分子和药物靶点。其中一个例子是结构独特的 β-内酯 obafluin，由荧光假单胞菌 ATCC 39502 产生。obafluin 对革兰氏阳性和阴性病原体均具有活性。然而，生物学目标尚不清楚。我们现在报道，obafluin 靶向苏氨酰-tRNA 合成酶，并且我们鉴定了同源物 ObaO，它赋予 obafluin 生产者免疫力。干扰ofobaOinP。 florescensATCC 39502 导致 obafluin 敏感性，而在sensitiveE.粘菌素赋予抵抗力。酶测定证明E. colithreonyl-tRNA 合成酶被 obafluin 完全抑制，而 ObaO 仅部分敏感，表现出非常不寻常的部分抑制机制。总而言之，我们的数据强调了免疫引导方法在从头鉴定抗生素靶标方面的实用性，并且最终将能够产生改进的奥巴氟林变体。
To meet the ever-growing demands of antibiotic discovery, new chemical matter and antibiotic targets are urgently needed. Many potent natural product antibiotics which were previously discarded can also provide lead molecules and drug targets. One such example is the structurally unique β-lactone obafluorin, produced byPseudomonas fluorescensATCC 39502. Obafluorin is active against both Gram-positive and -negative pathogens; however, the biological target was unknown. We now report that obafluorin targets threonyl-tRNA synthetase, and we identify a homologue, ObaO, which confers immunity to the obafluorin producer. Disruption ofobaOinP. fluorescensATCC 39502 results in obafluorin sensitivity, whereas expression in sensitiveE. colistrains confers resistance. Enzyme assays demonstrate thatE. colithreonyl-tRNA synthetase is fully inhibited by obafluorin, whereas ObaO is only partly susceptible, exhibiting a very unusual partial inhibition mechanism. Altogether, our data highlight the utility of an immunity-guided approach for the identification of an antibiotic targetde novoand will ultimately enable the generation of improved obafluorin variants.