Bactobolin resistance is conferred by mutations in the L2 ribosomal protein.
Bactobolin resistance is conferred by mutations in the L2 ribosomal protein.
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DOI：
10.1128/mbio.00499-12
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发表时间：
2012-12-18
期刊：
影响因子：
6.4
通讯作者：
Greenberg EP
中科院分区：
文献类型：
--
作者：
Chandler JR;Truong TT;Silva PM;Seyedsayamdost MR;Carr G;Radey M;Jacobs MA;Sims EH;Clardy J;Greenberg EP
泰兰伯克霍尔德氏菌产生一种名为杆菌素的聚酮多肽分子家族，其中一些是有效的抗生素。我们发现，巴氏杆菌在30℃比37℃生长可以增加杆菌素的产量。我们纯化了三种含量最丰富的杆菌素，并测定了它们对一组细菌和小鼠成纤维细胞的活性。三个化合物中有两个对细菌和成纤维细胞都有很强的抑制作用。第三个类似物在两种检测中的效力都要低得多。这些结果表明，杆菌素的靶标在细菌和哺乳动物细胞中可能是保守的。为了了解杆菌素的活性机制，我们分离了四株自然产生的枯草芽孢杆菌抗杆菌素突变体。我们使用基因组测序技术显示，四个耐药变异体中的每一个都在rplB中发生了突变，rplB编码50s核糖体相关的L2蛋白。突变的rplB基因在野生型枯草杆菌中的异位表达使其对杆菌素产生抗性。最后，L2突变不会对其他已知干扰核糖体功能的抗生素产生耐药性。我们的数据表明，杆菌素针对的是L2蛋白或附近的位置，而这不是其他抗生素的目标。我们推测杆菌素的哺乳动物靶标涉及L2(L8e)的真核同源物。目前可用的抗生素针对的细胞功能令人惊讶地少，因此需要确定新的抗生素靶点。我们一直对伯克霍尔德氏杆菌杆菌素感兴趣，我们试图通过在对杆菌素敏感的枯草杆菌中定位自发的耐药性突变来了解杆菌素活性的靶点。我们的结果表明，杆菌素的靶标是50S核糖体相关的L2蛋白或受L2影响的核糖体区域。抗菌素突变体对其他已知的核糖体抑制剂不耐药。我们的证据表明，杆菌素与一种新的抗生素靶点相互作用。
Burkholderia thailandensis produces a family of polyketide-peptide molecules called bactobolins, some of which are potent antibiotics. We found that growth of B. thailandensis at 30°C versus that at 37°C resulted in increased production of bactobolins. We purified the three most abundant bactobolins and determined their activities against a battery of bacteria and mouse fibroblasts. Two of the three compounds showed strong activities against both bacteria and fibroblasts. The third analog was much less potent in both assays. These results suggested that the target of bactobolins might be conserved across bacteria and mammalian cells. To learn about the mechanism of bactobolin activity, we isolated four spontaneous bactobolin-resistant Bacillus subtilis mutants. We used genomic sequencing technology to show that each of the four resistant variants had mutations in rplB, which codes for the 50S ribosome-associated L2 protein. Ectopic expression of a mutant rplB gene in wild-type B. subtilis conferred bactobolin resistance. Finally, the L2 mutations did not confer resistance to other antibiotics known to interfere with ribosome function. Our data indicate that bactobolins target the L2 protein or a nearby site and that this is not the target of other antibiotics. We presume that the mammalian target of bactobolins involves the eukaryotic homolog of L2 (L8e). Currently available antibiotics target surprisingly few cellular functions, and there is a need to identify novel antibiotic targets. We have been interested in the Burkholderia thailandensis bactobolins, and we sought to learn about the target of bactobolin activity by mapping spontaneous resistance mutations in the bactobolin-sensitive Bacillus subtilis. Our results indicate that the bactobolin target is the 50S ribosome-associated L2 protein or a region of the ribosome affected by L2. Bactobolin-resistant mutants are not resistant to other known ribosome inhibitors. Our evidence indicates that bactobolins interact with a novel antibiotic target.