PDF(Pubmed)
Abstract：
The foodborne pathogenic bacterium Campylobacter jejuni utilizes chemotaxis to assist in the colonization of host niches. A key to revealing the relationship among chemotaxis and pathogenicity is the discovery of signaling molecules perceived by the chemoreceptors. The C. jejuni chemoreceptor Tlp11 is encoded by the highly infective C. jejuni strains. In the present study, we report that the dCache-type ligand-binding domain (LBD) of C. jejuni ATCC 33560 Tlp11 binds directly to novel ligands methyl pyruvate, toluene, and quinoline using the same pocket. Methyl pyruvate elicits a strong chemoattractant response, while toluene and quinoline function as the antagonists without triggering chemotaxis. The sensory LBD was used to control heterologous proteins by constructing chimeras, indicating that the signal induced by methyl pyruvate is transmitted across the membrane. In addition, bioinformatics and experiments revealed that the dCache domains with methyl pyruvate-binding sites and ability are widely distributed in the order Campylobacterales. This is the first report to identify the class of dCache chemoreceptors that bind to attractant methyl pyruvate and antagonists toluene and quinoline. Our research provides a foundation for understanding the chemotaxis and virulence of C. jejuni and lays a basis for the control of this foodborne pathogen.
摘要：
食源性致病菌空肠弯曲杆菌利用趋化性来辅助宿主生态位的定植。揭示趋化性和致病性之间关系的关键是发现化学感受器感知的信号分子。空肠杆菌化学感受器Tlp11由高度感染性空肠杆菌菌株编码。在本研究中,我们报道空肠弯曲杆菌ATCC33560Tlp11的dCache型配体结合域（LBD）直接结合新的配体丙酮酸甲酯，甲苯,和喹啉用同一个口袋.丙酮酸甲酯引起强烈的化学引诱反应，而甲苯和喹啉起拮抗剂作用而不引发趋化性。感觉LBD通过构建嵌合体来控制异源蛋白，表明丙酮酸甲酯诱导的信号跨膜传递。此外,生物信息学和实验表明，具有丙酮酸甲酯结合位点和能力的dCache结构域以弯曲杆菌的顺序广泛分布。这是鉴定与引诱剂丙酮酸甲酯和拮抗剂甲苯和喹啉结合的dCache化学感受器类别的第一份报告。我们的研究为了解空肠弯曲菌的趋化性和毒力奠定了基础，并为控制这种食源性病原体奠定了基础。
