Patent ID: 7465544

Claim:
A method of derivatizing a methyltransferase substrate comprising: providing (i) a methyltransferase substrate selected from the group consisting of a nucleic acid and a polynucleotide, (ii) a methyltransferase, and (iii) a cofactor analog, wherein the cofactor analog is modified at its 5′ carbon atom to result in site-specific covalent ligation of the cofactor analog to the methyltransferase substrate by the methyltransferase and wherein the cofactor analog further includes at least one reacting group allowing for ligation of the cofactor analog to a detectable label; and reacting the methyltransferase substrate, the methyltransferase, and the cofactor analog under conditions wherein the co-factor analog ligates to the methyltransferase substrate in a reaction catalyzed by the methyltransferase.