In enzymology, an adenylyl-sulfate kinase (EC 2.7.1.25) is an enzyme that catalyzes the chemical reaction

ATP + adenylyl sulfate ${\displaystyle \rightleftharpoons }$ ADP + 3'-phosphoadenylyl sulfate

Thus, the two substrates of this enzyme are ATP and adenylyl sulfate, whereas its two products are ADP and 3'-phosphoadenylyl sulfate.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:adenylyl-sulfate 3'-phosphotransferase. Other names in common use include adenylylsulfate kinase (phosphorylating), 5'-phosphoadenosine sulfate kinase, adenosine 5'-phosphosulfate kinase, adenosine phosphosulfate kinase, adenosine phosphosulfokinase, adenosine-5'-phosphosulfate-3'-phosphokinase, and APS kinase. This enzyme participates in 3 metabolic pathways: purine metabolism, selenoamino acid metabolism, and sulfur metabolism.

This enzyme contains an ATP binding P-loop motif.^[1]

As of late 2007, 11 structures have been solved for this class of enzymes, with PDB accession codes 1D6J, 1M7G, 1M7H, 1X6V, 1XJQ, 1XNJ, 2AX4, 2GKS, 2OFW, 2OFX, and 2PEY.