In enzymology, a mRNA (2'-O-methyladenosine-N6-)-methyltransferase (EC 2.1.1.62) is an enzyme that catalyzes the chemical reaction S-adenosyl-L-methionine + m7G(5')pppAm S-adenosyl-L-homocysteine + m7G(5')pppm6Am (mRNA containing an N6,2'-O-dimethyladenosine cap) Thus, the two substrates of this enzyme are S-adenosyl methionine and , whereas its two products are S-adenosylhomocysteine and (mRNA containing an N6,2'-O-dimethyladenosine cap).