Requires pyridoxal 5'-phosphate. The enzyme, characterized from several bacterial species, is known to participate in L-arginine degradation and in the biosynthesis of the rare amino acid (3R)-3-methyl-L-arginine. The enzyme from Streptomyces arginensis also catalyses the activity of EC 2.6.1.126, L-aspartate:5-guanidino-3-methyl-2-oxopentanoate transaminase.
