This entry represents a group of RNA methyltransferases, including TK0422 from Thermococcus kodakaraensis and Sfm1 from Saccharomyces cerevisiae. TK0422 catalyzes the S-adenosyl-L-methionine-dependent formation of either N(1)-methyladenine or N(1)-methylguanine at position 9 (m1A9 or m1G9) in tRNA. Sfm1 (YOR021C) is a S-adenosyl-L-methionine-dependent protein-arginine N-methyltransferase that monomethylates ribosomal protein S3 (RPS3) at 'Arg-146'.