Member of the two-component regulatory system AruS/AruR, which is involved in the regulation of the arginine transaminase (ATA) pathway in response to exogeneous L-arginine. Regulates transcription of aruH and aruI. Amino-acid degradation; L-arginine degradation [regulation]. Phosphorylated by AruS. Disruption in the aruF mutant prevents growth on L-arginine.