Cryo-EM Structure and Molecular Dynamics Analysis of the Fluoroquinolone Resistant Mutant of the AcrB Transporter fromSalmonella
Cryo-EM Structure and Molecular Dynamics Analysis of the Fluoroquinolone Resistant Mutant of the AcrB Transporter fromSalmonella
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DOI：
10.3390/microorganisms8060943
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发表时间：
2020-06-01
期刊：
影响因子：
4.5
通讯作者：
Bavro, Vassiliy N.
中科院分区：
文献类型：
--
作者：
Johnson, Rachel M.;Fais, Chiara;Bavro, Vassiliy N.
沙门氏菌是一种重要的革兰氏阴性病原体属，由于抗菌素耐药性的增加，其治疗已成为问题。这部分归因于三方外排泵的过度表达，特别是组成性表达的AcrAB-TolC。尽管具有重要的临床意义，但沙门氏菌acrb转运体的结构至今仍不为人所知，我们对其结构的了解大部分来自大肠杆菌。在这里，利用苯乙烯马来酸（SMA）技术分离具有密切相关脂质的膜蛋白，我们报道了沙门氏菌acrb转运蛋白的第一个实验结构。此外，这种新的结构为药物外排机制提供了额外的见解，因为它携带突变（G288D），源自对氟喹诺酮类药物耐药性增强的伤寒沙门氏菌临床分离株。实验数据由最先进的分子动力学（MD）模拟对野生型和G288D型沙门氏菌acrb进行了补充。总之，这些揭示了关于theE的几个重要区别。该研究提供了对G288D突变在增加药物外排中的作用的见解，并扩展了我们对抗生素耐药性机制的理解。
Salmonellais an important genus of Gram-negative pathogens, treatment of which has become problematic due to increases in antimicrobial resistance. This is partly attributable to the overexpression of tripartite efflux pumps, particularly the constitutively expressed AcrAB-TolC. Despite its clinical importance, the structure of theSalmonellaAcrB transporter remained unknown to-date, with much of our structural understanding coming from theEscherichia coliorthologue. Here, by taking advantage of the styrene maleic acid (SMA) technology to isolate membrane proteins with closely associated lipids, we report the very first experimental structure ofSalmonellaAcrB transporter. Furthermore, this novel structure provides additional insight into mechanisms of drug efflux as it bears the mutation (G288D), originating from a clinical isolate ofSalmonellaTyphimurium presenting an increased resistance to fluoroquinolones. Experimental data are complemented by state-of-the-art molecular dynamics (MD) simulations on both the wild type and G288D variant ofSalmonellaAcrB. Together, these reveal several important differences with respect to theE. coliprotein, providing insights into the role of the G288D mutation in increasing drug efflux and extending our understanding of the mechanisms underlying antibiotic resistance.