Transport of D-galacturonate (PubMed:8320243, Ref.1). Cannot transport the dimer digalacturonic acid (PubMed:8320243). Uptake is an active process (PubMed:8320243). aldehydo-D-galacturonate(out) + H(+)(out) = aldehydo-D-galacturonate(in) + H(+)(in) Inhibited by cyanide and 2,4-dinitrophenol, but not by arsenate. Induced in the presence of D-galacturonate (Ref.1, PubMed:9530868, PubMed:11386378). Expression is regulated by ExuR (PubMed:11386378). Maximal transcription activity is observed within 8 hours of bacterial inoculation into potato tubers, well before any visible symptoms of disease are detected (PubMed:11386378). Mutation of the gene causes a reduction in growth on D-galacturonate and maceration of potato tuber tissue. Belongs to the major facilitator superfamily. Phthalate permease family.