Immunity-Guided Identification of Threonyl-tRNA Synthetase as the Molecular Target of Obafluorin, a ß-Lactone Antibiotic.
Immunity-Guided Identification of Threonyl-tRNA Synthetase as the Molecular Target of Obafluorin, a ß-Lactone Antibiotic.
复制标题
免疫引导下鉴定苏氨酰-tRNA 合成酶作为奥巴氟林（一种 β-内酯抗生素）的分子靶标。
DOI：
10.1021/acschembio.9b00590
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发表时间：
2019
影响因子：
4
通讯作者：
Scott TA
中科院分区：
文献类型：
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作者：
Scott TA
为了满足不断增长的抗生素发现需求，迫切需要新的化学物质和抗生素靶标。许多以前被丢弃的有效天然产物抗生素也可以提供先导分子和药物靶点。一个这样的例子是由荧光假单胞菌ATCC 39502产生的结构独特的β-内酯objorin。obbiliorin对革兰氏阳性和阴性病原体都有活性;然而，生物学靶标未知。我们现在报告说，obeorin目标苏氨酰-tRNA合成酶，我们确定了一个同源物，ObaO，它赋予免疫obeorin生产商。在P. fluorescensATCC 39502的表达导致obbeverin的敏感性，而在sensitiveE.大肠杆菌菌株赋予抗性。酶活性测定表明，E.大肠杆菌苏氨酰-tRNA合成酶完全被ObaO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指导方法在识别抗生素靶点方面的实用性，并最终能够产生改进的obafluorin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.