label: a 5'-end FAD-phospho-ribonucleoside in mRNA + H2O <=> a 5'-end phospho-ribonucleoside in mRNA + FAD + H(+)
label_lc: a 5'-end fad-phospho-ribonucleoside in mrna + h2o <=> a 5'-end phospho-ribonucleoside in mrna + fad + h(+)