Positively regulates the dhaKLM operon from a sigma-70 promoter. Represses its own expression. Homodimer. DhaR forms complexes with DhaK and DhaL-ADP. Represses its own expression. DhaL and DhaK act antagonistically as coactivator and corepressor of the transcription activator by mutually exclusive binding to the sensing domain of DhaR. In the presence of dihydroxyacetone, DhaK that binds dihydroxyacetone has less affinity for DhaR and is displaced by DhaL-ADP, which stimulates DhaR activity. In the absence of dihydroxyacetone, DhaL-ADP is converted by the PTS to DhaL-ATP, which does not bind to DhaR.