Mycobacterial HflX is a ribosome splitting factor that mediates antibiotic resistance
Mycobacterial HflX is a ribosome splitting factor that mediates antibiotic resistance
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DOI：
10.1073/pnas.1906748117
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发表时间：
2019-12
期刊：
影响因子：
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通讯作者：
Paulami Rudra;Kelley R. Hurst-Hess;Katherine L. Cotten;Andrea Partida-Miranda;P. Ghosh
中科院分区：
文献类型：
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作者：
Paulami Rudra;Kelley R. Hurst-Hess;Katherine L. Cotten;Andrea Partida-Miranda;P. Ghosh
erm 41基因被认为是结核分枝杆菌对大环内酯类内在耐药的主要机制。在这里，我们证明了hflX基因起着与erm 41同样重要的作用。我们进一步描述了一种不寻常的机制，大环内酯类-林可酰胺类抗生素介导的分枝杆菌HflX，可能涉及的分离的抗生素停滞的核糖体。了解细菌对抗生素产生耐药性的各种机制对于预测针对致病性分离株的有效治疗方案至关重要，并且还可以为新药的开发提供信息。细菌中的抗生素耐药性通常由作为外排泵或修饰药物或抗生素靶标的酶的蛋白质赋予。在这里，我们报告了一个不寻常的机制，耐药大环内酯类林可酰胺类抗生素介导的分枝杆菌HflX，一个保守的核糖体相关的GTP酶。我们发现，在致病性结核分枝杆菌中hflX基因的缺失，以及非致病性耻垢分枝杆菌，导致对大环内酯类-林可酰胺类抗生素的超敏反应。重要的是，Mab_hflX提供的抗性水平与erm 41赋予的抗性水平相当，这意味着hflX构成M中的重要抗性决定因素。你好我们证明，分枝杆菌HflX协会与50 S核糖体亚基在体内，并可以解离纯化的70 S核糖体在体外，独立的GTP水解。ΔMs_hflX菌株中HflX的缺失也导致红霉素暴露后70 S核糖体的显著积累。最后，HflX的N-末端或C-末端结构域的缺失消除了核糖体分裂，并伴随着消除了突变蛋白介导抗生素耐受性的能力。总之，我们的研究结果表明，大环内酯类-林可酰胺耐药的机制，其中分枝杆菌HflX解离的astrocytic-stalled核糖体和拯救绑定的mRNA。鉴于hflX基因的广泛存在，我们预计这是几种细菌使用的大环内酯类耐药的一般机制。
Significance The erm41 gene is considered the primary mechanism of intrinsic resistance to macrolides in Mycobacterium abscessus. Here we demonstrate that the hflX gene plays a significant and equally important role as erm41. We further describe an unusual mechanism of resistance to macrolide-lincosamide antibiotics mediated by the mycobacterial HflX that likely involves the dissociation of antibiotic-stalled ribosomes. An understanding of the various mechanisms employed by bacteria for resistance to an antibiotic is critical in predicting an effective therapeutic regimen against a pathogenic isolate, and can also inform the development of novel drugs. Antibiotic resistance in bacteria is typically conferred by proteins that function as efflux pumps or enzymes that modify either the drug or the antibiotic target. Here we report an unusual mechanism of resistance to macrolide-lincosamide antibiotics mediated by mycobacterial HflX, a conserved ribosome-associated GTPase. We show that deletion of the hflX gene in the pathogenic Mycobacterium abscessus, as well as the nonpathogenic Mycobacterium smegmatis, results in hypersensitivity to the macrolide-lincosamide class of antibiotics. Importantly, the level of resistance provided by Mab_hflX is equivalent to that conferred by erm41, implying that hflX constitutes a significant resistance determinant in M. abscessus. We demonstrate that mycobacterial HflX associates with the 50S ribosomal subunits in vivo and can dissociate purified 70S ribosomes in vitro, independent of GTP hydrolysis. The absence of HflX in a ΔMs_hflX strain also results in a significant accumulation of 70S ribosomes upon erythromycin exposure. Finally, a deletion of either the N-terminal or the C-terminal domain of HflX abrogates ribosome splitting and concomitantly abolishes the ability of mutant proteins to mediate antibiotic tolerance. Together, our results suggest a mechanism of macrolide-lincosamide resistance in which the mycobacterial HflX dissociates antibiotic-stalled ribosomes and rescues the bound mRNA. Given the widespread presence of hflX genes, we anticipate this as a generalized mechanism of macrolide resistance used by several bacteria.