The dCache Domain of the Chemoreceptor Tlp1 in Campylobacter jejuni Binds and Triggers Chemotaxis toward Formate
Jingjing Duan, Qi Zhao, Yuxin Wang, Zhe Chi, Wei Li, Xue Wang, Shuang‐Jiang Liu, Shuangyu Bi
Abstract
Chemotaxis is important for Campylobacter jejuni to colonize favorable niches in the gastrointestinal tract of its host. However, there is still a lack of knowledge about the ligand molecules for C. jejuni chemoreceptors. The dCache-type chemoreceptor, namely, Tlp1, is the most conserved chemoreceptor in C. jejuni strains; however, the direct-binding ligand(s) triggering chemotaxis has not yet been discovered. In the present study, we found that the ligand that binds directly to Tlp1-LBD with high specificity is formate. C. jejuni exhibits robust chemoattraction toward formate, primarily via Tlp1. Tlp1 is the first reported dCache-type chemoreceptor that specifically binds formate and triggers strong chemotaxis. We further demonstrated that the formate-mediated promotion of C. jejuni growth is correlated with Tlp1-mediated chemotaxis toward formate. Our work provides important insights into the mechanism and physiological function of chemotaxis toward formate and will facilitate further investigations into the involvement of microbial chemotaxis in pathogen-host interactions.