Steroid sulfotransferase
Class of enzymes
From Wikipedia, the free encyclopedia
A steroid sulfotransferase (EC 2.8.2.15) is an enzyme that catalyzes the general chemical reaction
It uses the cofactor 3'-phosphoadenosine-5'-phosphosulfate (PAPS) and gives adenosine 3',5'-bisphosphate as a byproduct. For example, the enzyme characterised from adrenal glands converts estradiol to estradiol sulfate:[1]
This enzyme is a transferase, specifically a sulfotransferase, which transfer sulfur-containing groups. The systematic name of this enzyme class is 3'-phosphoadenylyl-sulfate:phenolic-steroid sulfotransferase. This enzyme is also called steroid alcohol sulfotransferase.[2]
Genes
Of 62 sulfotransferase genes in the human genome, 16 represent cytoplasmic sulfotransferases, and of these 16 cytoplasmic sulfotransferases, five have been found to act as steroid sulfotransferases.[3] These five sulfotransferase genes are SULT1A1, SULT1E1, and SULT2A1, as well as the two isoforms of SULT2B1, SULT2B1a and SULT2B1b.[3] Their substrate specificity is as follows:[3]
- SULT1A1: Estradiol (to estradiol sulfate)
- SULT1E1: DHEA (to DHEA sulfate); Estrone (to estrone sulfate); Estradiol (to estradiol sulfate)
- SULT2A1: DHEA (to DHEA sulfate); Androsterone (to androsterone sulfate); Pregnenolone (to pregnenolone sulfate)
- SULT2B1a: Pregnenolone (to pregnenolone sulfate)
- SULT2B1b: Cholesterol (to cholesterol sulfate)
Traditionally, steroid sulfotransferases have been named according to their preferred substrate, for instance estrogen sulfotransferase (SULT1E1) and DHEA sulfotransferase (SULT2A1).[3] However, cytosolic steroid sulfotransferases show broad substrate specificity, and SULT1E1 and SULT2A1 are not the only steroid sulfotransferases that sulfate estrogens and DHEA, respectively.[3]
