Catalyzes electroneutral exchange between arginine and ornithine to allow high-efficiency energy conversion in the arginine deiminase pathway (PubMed:1311296, PubMed:8449902). Also mediates the proton motive force-driven uptake of arginine and ornithine, but the exchange is several orders of magnitude faster than the proton motive force-driven transport (PubMed:1311296). L-arginine(out) + L-ornithine(in) = L-arginine(in) + L-ornithine(out) Mutant is unable to utilize extracellular arginine as an energy source under oxygen-limiting or anaerobic conditions. Belongs to the amino acid-polyamine-organocation (APC) superfamily. Basic amino acid/polyamine antiporter (APA) (TC 2.A.3.2) family.