label: a 5'-end (N(2),N(7)-dimethyl 5'-triphosphoguanosine)-ribonucleoside in snoRNA + S-adenosyl-L-methionine = a 5'-end (N(2),N(2),N(7)-trimethyl 5'-triphosphoguanosine)-ribonucleoside in snoRNA + S-adenosyl-L-homocysteine + H(+)
label_lc: a 5'-end (n(2),n(7)-dimethyl 5'-triphosphoguanosine)-ribonucleoside in snorna + s-adenosyl-l-methionine = a 5'-end (n(2),n(2),n(7)-trimethyl 5'-triphosphoguanosine)-ribonucleoside in snorna + s-adenosyl-l-homocysteine + h(+)