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. All amino acids serve as attractants in B.subtilis, they appear to cause an increase in the turnover methyl groups, leading to methylation of an unidentified acceptor, while repellents have been shown to cause a decrease in methyl group turnover. The methyl groups are added by a methyltransferase and removed by a methylesterase. McpA is required for taxis towards glucose and alpha-methylglucoside. Interacts with FloT. Present in detergent-resistant membrane (DRM) fractions that may be equivalent to eukaryotic membrane rafts; these rafts include proteins involved in signaling, molecule trafficking and protein secretion. Deamidated by CheD on Gln-593 and Gln-594, producing glutamate residues. The glutamate residues are then methylated. Other additional sites are deamidated and methylated as well. Belongs to the methyl-accepting chemotaxis (MCP) protein family.