ENTRY       EC 2.7.7.53
NAME        ATP adenylyltransferase
            Bis(5'-nucleosyl)-tetraphosphate phosphorylase
            $ (NDP-forming)
            Diadenosinetetraphosphate alphabeta-phosphorylase
CLASS       Transferases
            Transferring phosphorus-containing groups
            Nucleotidyltransferases
SYSNAME     ADP:ATP adenylyltransferase
REACTION    ADP + ATP = Orthophosphate + P1,P4-Bis(5'-adenosyl) tetraphosphate
SUBSTRATE   ADP
            ATP
            GTP
            Adenosine tetraphosphate
PRODUCT     Orthophosphate
            P1,P4-Bis(5'-adenosyl) tetraphosphate
            P1,P5-Bis(5'-adenosyl) pentaphosphate
COMMENT     GTP and adenosine tetraphosphate can also act as adenylyl
            acceptors.
PATHWAY     PATH: MAP00230  Purine metabolism
GENES       SCE: YCL050C(APA1) YDR530C(APA2)
DBLINKS     University of Geneva ENZYME DATA BANK: 2.7.7.53
            WIT (What Is There) Metabolic Reconstruction: 2.7.7.53
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