Signal transducer for aerotaxis. The aerotactic response is the accumulation of cells around air bubbles. The nature of the sensory stimulus detected by this protein is the proton motive force or cellular redox state. It uses a FAD prosthetic group as a redox sensor to monitor oxygen levels. Predominantly localized to one cell pole in mid-to-late exponential phase, with a few smaller foci elsewhere in the cell. Belongs to the methyl-accepting chemotaxis (MCP) protein family.