This eukaryotic enzyme catalyses the sequential dimethylation of one of the terminal guanidino nitrogen atoms in arginine residues, resulting in formation of asymmetric dimethylarginine residues. Some forms (e.g. PRMT1) have a very wide substrate specificity, while others (e.g. PRMT4 and PRMT6) are rather specific. The enzyme has a preference for methylating arginine residues that are flanked by one or more glycine residues [1]. PRMT1 is responsible for the bulk (about 85%) of total protein arginine methylation activity in mammalian cells [2]. cf. EC 2.1.1.320, type II protein arginine methyltransferase, EC 2.1.1.321, type III protein arginine methyltransferase, and EC 2.1.1.322, type IV protein arginine methyltransferase.
