a 5'-end NAD(+)-phospho-ribonucleoside in mRNA + H2O => a 5'-end phospho-ribonucleoside in mRNA + NAD(+) + H(+)
a 5'-end nad(+)-phospho-ribonucleoside in mrna + h2o => a 5'-end phospho-ribonucleoside in mrna + nad(+) + h(+)