A novel chemoreceptor MCP2983 from Comamonas testosteroni specifically binds to cis-aconitate and triggers chemotaxis towards diverse organic compounds.

摘要: Comamonas testosteroni CNB-1 behaves chemotactically toward a wide range of organic compounds, and 19 methyl-accepting chemotaxis proteins (MCPs) were annotated from the genome strain CNB-2, plasmid-curing derivative CNB-1. The MCP-free mutant CNB-1Δ20 completely lost its chemotactic responses. In this study, we found that chemoreceptor, namely MCP2983, restored responses nine carboxylic acids ten aromatic compounds to CNB-1Δ20. Isothermal titration calorimetry analysis indicated ligand-binding domain (LBD) MCP2983 specifically binds cis-aconitate but not other tested compounds. Deletion LBD impaired as well indicating was essential for triggering Five amino acid residues (M81, S156, E157, I158, L159) are located at putative pocket identified be involved in binding cis-aconitate. So far, represents sole biochemically chemoreceptor is able trigger towards diverse