Utilization of L-Methionine and S-Adenosyl-L-methionine for Methylation of Soluble RNA by Mouse Liver and Hepatoma Extracts1

amounts of methyl incorporation. Other nucleoside triphosphates besides adenosine triphosphate were capable of sup]x>rting the incorjioration of methyl groups from L-methionine into sRNA. The nonspecificity of the nucleoside triphosphate reaction was shown to be due to an adenosine diphosphokinase reaction and not to nucleoside tri phosphate: L-methionine nucleosidyl transferase activity. Mouse hepatoma BW7756 was found to have lower amounts of methylation activity than mouse liver if L-methionine-14CH3