. "The bifunctional enzyme from Mycobacterium tuberculosis 2'-O-methylates cytidine(1409) in helix 44 of 16S rRNA and cytidine(1920) in helix 69 of 23S rRNA (cf. EC 2.1.1.226)." . . . "16S rRNA (cytidine(1409)-2'-O)-methyltransferase" . "S-adenosyl-L-methionine + cytidine(1409) in 16S rRNA = S-adenosyl-L-homocysteine + 2'-O-methylcytidine(1409) in 16S rRNA." .