Catalyzes the reversible conversion of aspartate and 2-oxoglutarate to glutamate and oxaloacetate. Can also transaminate prephenate in the presence of glutamate. 2-oxoglutarate + L-aspartate = L-glutamate + oxaloacetate 2-oxoglutarate + L-arogenate = L-glutamate + prephenate Homodimer. Belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family.