Members of this family are the bifunctional aminotransferase that catalyzes the first and third steps in the three-step conversion of arginine to beta-methylarginine. It first converts arginine to 2-ketoarginine, then converts 3-methyl-2-ketoarginine to 3-methylarginine. All members of the seed alignment are encoded next to a 2-ketoarginine methyltransferase (EC 2.1.1.243).
Jiyao W et al.(2023). "The conserved domain database in 2023.",