ENTRY       EC 2.7.7.50
NAME        mRNA guanylyltransferase
            mRNA capping enzyme
CLASS       Transferases
            Transferring phosphorus-containing groups
            Nucleotidyltransferases
SYSNAME     GTP:mRNA guanylyltransferase
REACTION    GTP + (5')ppPur-mRNA = Pyrophosphate + G(5')pppPur-mRNA 
SUBSTRATE   GTP
            (5')ppPur-mRNA
            Poly(A)
            Poly(G)
PRODUCT     Pyrophosphate
            G(5')pppPur-mRNA
            m7G(5')pppAn
            m7G(5')pppGn
COMMENT     The enzyme can modify also synthetic poly(A) and poly(G) to
            form the structures m7G(5')pppAn and m7G(5')pppGn.  Product 
            G(5')pppPur-mRNA (mRNA containing a guanosine residue linked 5' 
            through three phosphates to the 5' position of the terminal 
            residue).
GENES       SCE: YGL130W(CEG1)
STRUCTURES  PDB: 1CKN  1CKM  
DBLINKS     University of Geneva ENZYME DATA BANK: 2.7.7.50
            WIT (What Is There) Metabolic Reconstruction: 2.7.7.50
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