IUBMB Enzyme Nomenclature


Accepted name: mRNA 5'-phosphatase

Reaction: a 5'-triphospho-[mRNA] + H2O = a 5'-diphospho-[mRNA] + phosphate

Other name(s): 5'-polynucleotidase; polynucleotide 5'-phosphohydrolase; RNGTT (gene name); CET1 (gene name); mRNA 5′-triphosphate monophosphatase

Systematic name: 5'-triphospho-mRNA 5'-phosphohydrolase

Comments: The enzyme, found in eukaryotes and some plus strand RNA viruses (e.g. alphavirus), is involved in mRNA capping. Unlike the eukaryotic enzyme, the viral enzyme requires a purine in the first position of the mRNA. The human enzyme is a multi domain protein that also has the activity of EC, mRNA guanylyltransferase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:


1. Itoh, N., Mizumoto, K. and Kaziro, Y. Messenger RNA guanlyltransferase from Saccharomyces cerevisiae. II. Catalytic properties. J. Biol. Chem. 259 (1984) 13930-13936. [PMID: 6094533]

2. Tsukamoto, T., Shibagaki, Y., Murakoshi, T., Suzuki, M., Nakamura, A., Gotoh, H. and Mizumoto, K. Cloning and characterization of two human cDNAs encoding the mRNA capping enzyme. Biochem. Biophys. Res. Commun. 243 (1998) 101-108. [PMID: 9473487]

3. Vasiljeva, L., Merits, A., Auvinen, P. and Kaariainen, L. Identification of a novel function of the alphavirus capping apparatus. RNA 5'-triphosphatase activity of Nsp2. J. Biol. Chem. 275 (2000) 17281-17287. [PMID: 10748213]

[EC created 2021]

Return to EC 3.6.1 home page
Return to EC 3.6 home page
Return to EC 3 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page