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. McpC is required for taxis to cysteine, proline, threonine, glycine, serine, lysine, valine and arginine and for aspartate, glutamine, histidine and glutamate. Primarily mediates response to positive stimulus of PTS carbohydrates. Greatly influences the duration or magnitude of the response to negative PTS carbohydrate stimulus.