In enzymology, an ATP adenylyltransferase () is an enzyme that catalyzes the chemical reaction

ADP + ATP \rightleftharpoons phosphate + P₁,P₄-bis(5'-adenosyl) tetraphosphate

Thus, the two substrates of this enzyme are ADP and ATP, whereas its two products are phosphate and P1,P4-bis(5'-adenosyl) tetraphosphate.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is ADP:ATP adenylyltransferase. Other names in common use include bis(5'-nucleosyl)-tetraphosphate phosphorylase (NDP-forming), diadenosinetetraphosphate alphabeta-phosphorylase, adenine triphosphate adenylyltransferase, diadenosine 5',5'"-P1,P4-tetraphosphate alphabeta-phosphorylase, (ADP-forming), and dinucleoside oligophosphate alphabeta-phosphorylase. This enzyme participates in purine metabolism.

References