The antibiotic resistance (ARE) subfamily of ABC (ATP-binding cassette) proteins confers resistance to a variety of clinically important ribosome-targeting antibiotics and plays an important role in infections caused by pathogenic bacteria. However, inhibitors of ARE proteins have rarely been reported. Here, OptrA, a new member of the ARE proteins, was used to study inhibitors of these types of proteins. We first confirmed that destroying the catalytic activity of OptrA could restore the sensitivity of host cells to antibiotics. Then, fragment-based screening, a drug screening method, was used to screen for inhibitors of OptrA. The competitive saturation transfer difference experiments, docking, and molecular dynamics were used to determine the binding sites and mode of interactions between OptrA and fragment screening hits. In this study, we first find a novel and specific inhibitor of OptrA (CP1), which suppressed the ATPase activity of OptrA in vitro by 30%. A hydrogen bond formed between the 8-position phenylcyclic cyano group in CP1 and the amino acid residue Lys-271 allows CP1 to form a stable complex with OptrA protein. These findings provide a theoretical basis for the further optimization of the inhibitor structure to obtain inhibitors with higher efficiencies.

中文翻译：

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新型抗生素抗性蛋白OptrA的新型抑制剂。

ABC（ATP结合盒）蛋白的抗生素抗性（ARE）子家族赋予了对多种临床上重要的靶向核糖体的抗生素的抗性，并且在由病原菌引起的感染中起着重要的作用。然而，很少报道ARE蛋白的抑制剂。在这里，AREtr蛋白的新成员OptrA被用于研究这类蛋白的抑制剂。我们首先证实破坏OptrA的催化活性可以恢复宿主细胞对抗生素的敏感性。然后，使用基于片段的筛选（一种药物筛选方法）来筛选OptrA抑制剂。竞争性饱和转移差异实验，对接和分子动力学被用来确定OptrA和片段筛选命中之间的结合位点和相互作用方式。在这项研究中，我们首先找到一种新型的特异性OptrA抑制剂（CP1），该抑制剂可在体外将OptrA的ATPase活性抑制30％。CP1的8位苯环氰基与氨基酸残基Lys-271之间形成的氢键使CP1与OptrA蛋白形成稳定的复合物。这些发现为进一步优化抑制剂结构以获得具有更高效率的抑制剂提供了理论基础。