ID 3.6.1.74 DE mRNA 5'-phosphatase. AN 5'-polynucleotidase. AN mRNA 5'-triphosphate monophosphatase. AN polynucleotide 5'-phosphohydrolase. CA a 5'-end triphospho-ribonucleoside in mRNA + H2O = a 5'-end diphospho- CA ribonucleoside in mRNA + H(+) + 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 O93803, CET1_CANAL ; Q6FUZ2, CET1_CANGA ; Q5KEQ1, CET1_CRYNJ ; DR Q6BND2, CET1_DEBHA ; Q755F7, CET1_EREGS ; Q6CT22, CET1_KLULA ; DR Q9P6Q6, CET1_SCHPO ; Q6C2H4, CET1_YARLI ; O13297, CET1_YEAST ; DR Q03220, CTL1_YEAST ; Q17607, MCE1_CAEEL ; Q6NY98, MCE1_DANRE ; DR O60942, MCE1_HUMAN ; O55236, MCE1_MOUSE ; Q8V2R8, MCEL_CAMPM ; DR Q775U0, MCEL_CAMPS ; Q8QMV9, MCEL_CWPXB ; Q80DX6, MCEL_CWPXG ; DR Q9J584, MCEL_FOWPN ; P25950, MCEL_RFVKA ; O57209, MCEL_VACCA ; DR P20979, MCEL_VACCC ; Q9JFA8, MCEL_VACCT ; P04298, MCEL_VACCW ; DR P0DSX5, MCEL_VAR67 ; P0DSX6, MCEL_VARV ; P32094, MCE_ASFB7 ; DR P0C995, MCE_ASFK5 ; Q65216, MCE_ASFM2 ; P0C993, MCE_ASFP4 ; DR P0C994, MCE_ASFWA ; Q5UQX1, MCE_MIMIV ; Q86924, POLN_AURAV ; DR P87515, POLN_BFV ; Q5XXP4, POLN_CHIK3 ; Q8JUX6, POLN_CHIKS ; DR Q306W6, POLN_EEEV1 ; Q306W8, POLN_EEEV8 ; Q4QXJ8, POLN_EEEVF ; DR P36327, POLN_EEVV3 ; Q8V294, POLN_EEVVC ; Q9WJC7, POLN_EEVVM ; DR P36328, POLN_EEVVP ; P27282, POLN_EEVVT ; Q5Y389, POLN_GETV ; DR Q8QZ73, POLN_MAYAB ; P13886, POLN_ONNVG ; O90370, POLN_ONNVI ; DR O90368, POLN_ONNVS ; P13887, POLN_RRVN ; Q9JGL0, POLN_SAGV ; DR P08411, POLN_SFV ; P27283, POLN_SINDO ; P03317, POLN_SINDV ; DR Q8QL53, POLN_SLDV ; Q8JJX1, POLN_SPDV ; P13896, POLN_WEEV ; //