Chemotactic-signal transducers respond to changes in the concentration of attractants and repellents in the environment, transduce a signal from the outside to the inside of the cell, and facilitate sensory adaptation through the variation of the level of methylation. Chemoreceptor for naphthalene or a related compound. May facilitate biodegradation. Mutant grows on naphthalene but is not chemotactic to this aromatic hydrocarbon. Mutant has a wild-type chemotactic response to succinate, benzoate, salicylate and 4-hydroxybenzoate. Belongs to the methyl-accepting chemotaxis (MCP) protein family.