Involved in both the arginine and lysine biosynthetic pathways. 2-oxoglutarate + N(2)-acetyl-L-ornithine = L-glutamate + N-acetyl-L-glutamate 5-semialdehyde 2-oxoglutarate + N-succinyl-(2S,6S)-2,6-diaminoheptanedioate = (S)-2-succinylamino-6-oxoheptanedioate + L-glutamate Binds 1 pyridoxal phosphate per subunit. Amino-acid biosynthesis; L-arginine biosynthesis; N(2)-acetyl-L-ornithine from L-glutamate: step 4/4. Amino-acid biosynthesis; L-lysine biosynthesis via DAP pathway; LL-2,6-diaminopimelate from (S)-tetrahydrodipicolinate (succinylase route): step 2/3. Homodimer. Belongs to the class-III pyridoxal-phosphate-dependent aminotransferase family. ArgD subfamily.