3'-Phosphoadenosine 5'-Phosphosulfate Synthase 2 (PAPSS2)

Three-prime-phosphoadenosine 5-prime-phosphosulfate (PAPS) is the sulfate donor cosubstrate for all sulfotransferase (SULT) enzymes. SULTs catalyze the sulfate conjugation of many endogenous and exogenous compounds, including drugs and other xenobiotics. In humans, PAPS is synthesized from adenosine 5-prime triphosphate (ATP) and inorganic sulfate by 2 isoforms, PAPSS1 and PAPSS2.

PAPSS2 consists of kinase and sulfurylase domains, and catalyzes 2 sequential reactions to synthesize PAPS. These reactions are catalyzed by separate enzymes encoded by 2 or 3 genes in simpler organisms. The human gene promoter has a GC-rich region with 9 potential SP1-binding sites.