Phosphoadenosine Phosphosulfate

**Definition:** 3'-Phosphoadenosine-5'-phosphosulfate. Key intermediate in the formation by living cells of sulfate esters of phenols, alcohols, steroids, sulfated polysaccharides, and simple esters, such as choline sulfate. It is formed from sulfate ion and ATP in a two-step process. This compound also is an important step in the process of sulfur fixation in plants and microorganisms.

**Tree numbers:** - D03.633.100.759.646.138.850 - D13.695.667.138.850 - D13.695.827.068.850

**Synonyms:** - Adenosine-3'-phosphate-5'-Phosphosulfate