Converts adenosine-3',5'-bisphosphate (PAP) to AMP. May also convert adenosine 3'-phosphate 5'-phosphosulfate (PAPS) to adenosine 5'-phosphosulfate (APS). Has 10000-fold lower activity towards inositol 1,4-bisphosphate (Ins(1,4)P2). adenosine 3',5'-bisphosphate + H2O = AMP + phosphate Inhibited by lithium and calcium. Strongly repressed during nitrogen excess. Mutants require cysteine or sulfite to grow under aerobic conditions. Belongs to the inositol monophosphatase superfamily. CysQ family. Was originally thought to be an ammonium transport protein.