This entry represents mRNA (guanine-N(7))-methyltransferase, which can either be found as a single domain protein, or as a domain within the mRNA-capping enzyme catalytic subunit. mRNA (guanine-N(7))-methyltransferase methylates the N7 position of the added guanosine to the 5'-cap structure of mRNAs. It binds RNA containing 5'-terminal GpppC [1-5]. Viral mRNA capping enzymes, meanwhile, are multidomain proteins that catalyse the first two reactions in the mRNA cap formation pathway [5]. They are heterodimers consisting of a large (catalytic) and small subunit.

1: Phylogeny of mRNA capping enzymes. Wang SP, Deng L, Ho CK, Shuman S; Proc Natl Acad Sci U S A 1997;94:9573-9578. PMID:9275164

2: Cloning and characterization of mRNA capping enzyme and mRNA (Guanine-7-)-methyltransferase cDNAs from Xenopus laevis. Yokoska J, Tsukamoto T, Miura Ki, Shiokawa K, Mizumoto K; Biochem Biophys Res Commun. 2000;268:617-624. PMID:10679253

3: Cloning and characterization of three human cDNAs encoding mRNA (guanine-7-)-methyltransferase, an mRNA cap methylase. Tsukamoto T, Shibagaki Y, Niikura Y, Mizumoto K; Biochem Biophys Res Commun. 1998;251:27-34. PMID:9790902

4: Molecular basis of RNA guanine-7 methyltransferase (RNMT) activation by RAM. Varshney D, Petit AP, Bueren-Calabuig JA, Jansen C, Fletcher DA, Peggie M, Weidlich S, Scullion P, Pisliakov AV, Cowling VH; Nucleic Acids Res. 2016;44:10423-10436. PMID:27422871

5: Crystal structure of vaccinia virus mRNA capping enzyme provides insights into the mechanism and evolution of the capping apparatus. Kyrieleis OJ, Chang J, de la Pena M, Shuman S, Cusack S; Structure. 2014;22:452-465. PMID:24607143