Protein arginine methylation is a form of post-translational modification that is catalyzed by protein arginine methyltransferases (PRMTs). PRMT6 catalyzes the sequential transfer of a methyl group from S-adenosyl-L-methionine to the side chain nitrogens of arginine residues within proteins to form methylated arginine derivatives and S-adenosyl-L-homocysteine. PRMT6 has been shown to act as a restriction factor for HIV replication.