mRNA guanylyltransferase

mRNA guanylyltransferase is a highly conserved enzyme that catalyzes the addition of a guanosine cap (m⁷GpppN) to the 5' end of nascent mRNA during transcription. This three-step mRNA capping process is crucial for mRNA stability, processing, nuclear export, and efficient translation. The enzyme mediates the second step in capping, transferring GMP from GTP to the diphosphate 5' end of pre-mRNA, forming the characteristic cap necessary for proper gene expression in eukaryotes. In mammals, a single bifunctional polypeptide often carries both the RNA triphosphatase and guanylyltransferase activities, while in yeast and many viruses, the enzymes are monofunctional or organized differently[1][2][3][4][5][7]. Structural studies in humans reveal conserved domains critical for substrate recognition and catalysis, with significant evolutionary divergence between mammalian and non-mammalian homologs[1][3][4][7].

Other names

mRNA capping enzymemessenger RNA guanylyltransferaseGTP:mRNA guanylyltransferaseProtein 2

Inhibitors (theoretical or investigational) would impede mRNA capping, leading to impaired mRNA stability and translation[1][3][5]