Reaction: a 5'-(N7-methyl 5'-triphosphoguanosine)-[mRNA] + H2O = N7-methylguanosine 5'-phosphate + a 5'-diphospho-[mRNA]
Other name(s): DcpS; m7GpppX pyrophosphatase; m7GpppN m7GMP phosphohydrolase; m7GpppX diphosphatase; m7G5'ppp5’N m7GMP phosphohydrolase
Systematic name: 5'-(N7-methyl 5'-triphosphoguanosine)-[mRNA] N7-methylguanosine 5'-phosphate phosphohydrolase
Comments: The enzyme removes (decaps) the N7-methylguanosine 5-phosphate cap from an mRNA degraded to a maximal length of 10 nucleotides [3,6]. Decapping is an important process in the control of eukaryotic mRNA degradation. The enzyme functions to clear the cell of cap structure following decay of the RNA body [2]. The nematode enzyme can also decap triply methylated substrates, 5'-(N2,N2,N7-trimethyl 5'-triphosphoguanosine)-[mRNA] [4].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Malys, N. and McCarthy, J.E. Dcs2, a novel stress-induced modulator of m7GpppX pyrophosphatase activity that locates to P bodies. J. Mol. Biol. 363 (2006) 370-382. [PMID: 16963086]
2. Liu, S.W., Rajagopal, V., Patel, S.S. and Kiledjian, M. Mechanistic and kinetic analysis of the DcpS scavenger decapping enzyme. J. Biol. Chem. 283 (2008) 16427-16436. [PMID: 18441014]
3. Liu, H., Rodgers, N.D., Jiao, X. and Kiledjian, M. The scavenger mRNA decapping enzyme DcpS is a member of the HIT family of pyrophosphatases. EMBO J. 21 (2002) 4699-4708. [PMID: 12198172]
4. van Dijk, E., Le Hir, H. and Seraphin, B. DcpS can act in the 5'-3' mRNA decay pathway in addition to the 3'-5' pathway. Proc. Natl. Acad. Sci. USA 100 (2003) 12081-12086. [PMID: 14523240]
5. Chen, N., Walsh, M.A., Liu, Y., Parker, R. and Song, H. Crystal structures of human DcpS in ligand-free and m7GDP-bound forms suggest a dynamic mechanism for scavenger mRNA decapping. J. Mol. Biol. 347 (2005) 707-718. [PMID: 15769464]
6. Cohen, L.S., Mikhli, C., Friedman, C., Jankowska-Anyszka, M., Stepinski, J., Darzynkiewicz, E. and Davis, R.E. Nematode m7GpppG and m3(2,2,7)GpppG decapping: activities in Ascaris embryos and characterization of C. elegans scavenger DcpS. RNA 10 (2004) 1609-1624. [PMID: 15383679]
7. Wypijewska, A., Bojarska, E., Lukaszewicz, M., Stepinski, J., Jemielity, J., Davis, R.E. and Darzynkiewicz, E. 7-Methylguanosine diphosphate (m7GDP) is not hydrolyzed but strongly bound by decapping scavenger (DcpS) enzymes and potently inhibits their activity. Biochemistry 51 (2012) 8003-8013. [PMID: 22985415]