EOG8J6V80 GO:0006370 1/9 7-methylguanosine mRNA capping biological_process "Addition of the 7-methylguanosine cap to the 5' end of a nascent messenger RNA transcript." [GOC:mah, PMID:9266685] EOG8J6V80 GO:0004484 1/9 mRNA guanylyltransferase activity molecular_function "Catalysis of the reaction: GTP + (5')pp-Pur-mRNA = diphosphate + G(5')ppp-Pur-mRNA; G(5')ppp-Pur-mRNA is mRNA containing a guanosine residue linked 5' through three phosphates to the 5' position of the terminal residue." [EC:2.7.7.50]