Listeria monocytogenes is a bacterial pathogen that controls much of its virulence through the transcriptional regulator PrfA. In this study, we describe structure-guided design and synthesis of a set of PrfA inhibitors based on ring-fused 2-pyridone heterocycles. Our most effective compound decreased virulence factor expression, reduced bacterial uptake into eukaryotic cells, and improved survival of chicken embryos infected with L. monocytogenes compared to previously identified compounds. Crystal structures identified an intraprotein “tunnel” as the main inhibitor binding site (A_I), where the compounds participate in an extensive hydrophobic network that restricts the protein’s ability to form functional DNA-binding helix–turn–helix (HTH) motifs. Our studies also revealed a hitherto unsuspected structural plasticity of the HTH motif. In conclusion, we have designed 2-pyridone analogues that function as site-A_I selective PrfA inhibitors with potent antivirulence properties.

中文翻译：

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基于结构的抑制剂靶向PrfA（单核细胞增生性李斯特菌的主要毒力调节剂）的设计

单核细胞增生李斯特菌是一种细菌病原体，可通过转录调节剂PrfA控制其大部分毒力。在这项研究中，我们描述了结构指导的设计和一组基于环稠合的2-吡啶酮杂环的PrfA抑制剂的合成。与以前鉴定的化合物相比，我们最有效的化合物降低了毒力因子的表达，减少了细菌对真核细胞的摄取，并提高了感染单核细胞增生李斯特菌的鸡胚的存活率。晶体结构确定蛋白内“隧道”为主要抑制剂结合位点（A _I），这些化合物会参与一个广泛的疏水网络，从而限制了蛋白质形成功能性DNA结合螺旋-转-螺旋（HTH）基序的能力。我们的研究还揭示了HTH母题迄今未曾想到的结构可塑性。总之，我们设计了2-吡啶酮类似物，其具有有效的抗病毒特性，可作为位点A _I选择性PrfA抑制剂。