Analysis of the Human 3’-Phosphoadenosine 5’-Phosphosulfate Synthase Genes

. PAPS is the universal sulfonate donor compound. PAPS synthase (PAPSS) catalyzes the formation PAPS in two concerted steps. In the first step SO4 combines with ATP to form adenosine 5’-phosphosulfate (APS) and PPi catalyzed by ATP sulfurylase domain. In the second step APS combines with another molecule of ATP to form PAPS and ADP catalyzed by APS kinase domain. In higher eukaryotes APS kinase domain (aa 1-268) and ATP sulfurylase domain (aa 220-623) are fused together into a single polypeptide termed PAPS synthase (PAPSS) (1). cDNA of the two isoforms PAPSS1 (accession # U53447) and PAPSS2b (accession # AF 150754) from human have been molecularly cloned and characterized[1]. PAPS synthase genes have been localized to chromosome 4q24 (PAPSS1) and chromosome 10q22.3-10q25.1 (PAPSS2)[1,2].