ID 3.6.1.74 DE mRNA 5'-phosphatase. AN 5'-polynucleotidase. AN mRNA 5'-triphosphate monophosphatase. AN Polynucleotide 5'-phosphohydrolase. CA A 5'-triphospho-[mRNA] + H(2)O = a 5'-diphospho-[mRNA] + phosphate. CC -!- The enzyme, found in eukaryotes and some plus strand RNA viruses CC (e.g. alphavirus), is involved in mRNA capping. CC -!- Unlike the eukaryotic enzyme, the viral enzyme requires a purine in CC the first position of the mRNA. CC -!- The human enzyme is a multi domain protein that also has the activity CC of EC 2.7.7.50. DR Q755F7, CET1_ASHGO ; O93803, CET1_CANAL ; Q6FUZ2, CET1_CANGA ; DR Q5KEQ1, CET1_CRYNJ ; Q6BND2, CET1_DEBHA ; Q6CT22, CET1_KLULA ; DR Q9P6Q6, CET1_SCHPO ; Q6C2H4, CET1_YARLI ; O13297, CET1_YEAST ; DR Q17607, MCE1_CAEEL ; Q6NY98, MCE1_DANRE ; O60942, MCE1_HUMAN ; DR O55236, MCE1_MOUSE ; //