Mitochondrial transporter of the positively charged amino acids ornithine, lysine and arginine, and the neutral amino acid citrulline (PubMed:12807890). In addition, transports the basic amino acids histidine, homoarginine, and asymmetric dimethylarginine (aDMA), but not symmetric DMA, and the D-forms of lysine, arginine, ornithine and histidine (PubMed:12807890, PubMed:26403849). Functions by both counter-exchange and uniport mechanisms (PubMed:26403849). . This is the function of SLC25A2 (solute carrier family 25 member 2, ENSG00000120329).