label: (N(7)-methyl 5'-triphospho-guanosine)-guanosine + a 5'-end phospho-ribonucleoside in mRNA + H(+) => a 5'-end (N(7)-methyl 5'-triphosphoguanosine)-guanosine-phospho-ribonucleoside in mRNA + H2O
label_lc: (n(7)-methyl 5'-triphospho-guanosine)-guanosine + a 5'-end phospho-ribonucleoside in mrna + h(+) => a 5'-end (n(7)-methyl 5'-triphosphoguanosine)-guanosine-phospho-ribonucleoside in mrna + h2o