Topoisomerase IV-quinolone interactions are mediated through a water-metal ion bridge: mechanistic basis of quinolone resistance.
Topoisomerase IV-quinolone interactions are mediated through a water-metal ion bridge: mechanistic basis of quinolone resistance.
复制标题
DOI：
10.1093/nar/gkt124
复制
发表时间：
2013-04
影响因子：
14.9
通讯作者：
Osheroff N
中科院分区：
文献类型：
--
作者：
Aldred KJ;McPherson SA;Turnbough CL Jr;Kerns RJ;Osheroff N
虽然喹诺酮类药物是最常用的抗菌药物，但其使用受到越来越多的耐药性的威胁。喹诺酮类药物耐药的最常见原因是旋转酶或拓扑异构酶IV A亚基中特定的丝氨酸或酸性残基的突变。这些氨基酸被认为是关键的酶-喹诺酮相互作用位点，通过锚定协调药物结合的水-金属离子桥来发挥作用。为了探索所提出的水-金属离子桥的作用，我们研究了野生型GrlAE85K、GrlAS81F/E85K、GrlAE85A、GrlAS81F/E85A和GrlAS81F炭疽杆菌拓扑异构酶IV，它们对喹诺酮类药物和相关药物的敏感性以及它们对金属离子的利用。突变增加了产生最大喹诺酮诱导的DNA切割所需的镁离子浓度，并限制了支持喹诺酮活性的二价金属离子。Ser81或Glu85的单独突变部分破坏了桥功能，而这两个残基的同时突变则破坏了蛋白质与喹诺酮类药物的相互作用。这些结果为水-金属离子桥的存在提供了功能证据，证实了丝氨酸和谷氨酸残基锚定了该桥，证明该桥是临床相关的喹诺酮类药物与拓扑异构酶IV相互作用的主要通道，并为最常见的喹诺酮类药物耐药提供了可能的机制。
Although quinolones are the most commonly prescribed antibacterials, their use is threatened by an increasing prevalence of resistance. The most common causes of quinolone resistance are mutations of a specific serine or acidic residue in the A subunit of gyrase or topoisomerase IV. These amino acids are proposed to serve as a critical enzyme-quinolone interaction site by anchoring a water-metal ion bridge that coordinates drug binding. To probe the role of the proposed water-metal ion bridge, we characterized wild-type, GrlAE85K, GrlAS81F/E85K, GrlAE85A, GrlAS81F/E85A and GrlAS81F Bacillus anthracis topoisomerase IV, their sensitivity to quinolones and related drugs and their use of metal ions. Mutations increased the Mg2+ concentration required to produce maximal quinolone-induced DNA cleavage and restricted the divalent metal ions that could support quinolone activity. Individual mutation of Ser81 or Glu85 partially disrupted bridge function, whereas simultaneous mutation of both residues abrogated protein–quinolone interactions. Results provide functional evidence for the existence of the water-metal ion bridge, confirm that the serine and glutamic acid residues anchor the bridge, demonstrate that the bridge is the primary conduit for interactions between clinically relevant quinolones and topoisomerase IV and provide a likely mechanism for the most common causes of quinolone resistance.
登录
查看更多内容
影响因子：
11.5
作者：
Hooper, DC
通讯作者：
Hooper, DC
影响因子：
2.9
作者：
Hiasa, H
通讯作者：
Hiasa, H
影响因子：
2.9
作者：
Anderson, VE;Zaniewski, RP;Osheroff, N
通讯作者：
Osheroff, N
影响因子：
4.9
作者：
German, Nadezhda;Malik, Muhammad;Kerns, Robert J.
通讯作者：
Kerns, Robert J.
影响因子：
64.8
作者：
Bax, Benjamin D.;Chan, Pan F.;Gwynn, Michael N.
通讯作者：
Gwynn, Michael N.