a 5'-end (N(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in snRNA + S-adenosyl-L-methionine <=> a 5'-end (N(2),N(7)-dimethyl 5'-triphosphoguanosine)-ribonucleoside in snRNA + S-adenosyl-L-homocysteine + H(+)
a 5'-end (n(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in snrna + s-adenosyl-l-methionine <=> a 5'-end (n(2),n(7)-dimethyl 5'-triphosphoguanosine)-ribonucleoside in snrna + s-adenosyl-l-homocysteine + h(+)
a 5'-end (N(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in snRNA + S-adenosyl-L-methionine <=> a 5'-end (N(2),N(7)-dimethyl 5'-triphosphoguanosine)-ribonucleoside in snRNA + S-adenosyl-L-homocysteine + H(+)
a 5'-end (n(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in snrna + s-adenosyl-l-methionine <=> a 5'-end (n(2),n(7)-dimethyl 5'-triphosphoguanosine)-ribonucleoside in snrna + s-adenosyl-l-homocysteine + h(+)