Estrone sulfotransferase (EST) (EC 2.8.2.4), also known as estrogen sulfotransferase, is an enzyme that catalyzes the transformation of an unconjugated estrogen like estrone into a sulfated estrogen like estrone sulfate. It is a steroid sulfotransferase and belongs to the family of transferases, to be specific, the sulfotransferases, which transfer sulfur-containing groups. This enzyme participates in androgen and estrogen metabolism and sulfur metabolism.

Steroid sulfatase is an enzyme that catalyzes the reverse reaction, the transfer of a sulfate to an unconjugated estrogen.

Reaction

In enzymology, an EST is an enzyme that catalyzes the following chemical reaction:

3'-phosphoadenylyl sulfate + estrone ${\displaystyle \rightleftharpoons }$ adenosine 3',5'-bisphosphate + estrone 3-sulfate

Thus, the two substrates of this enzyme are 3'-phosphoadenylyl sulfate and estrone, whereas its two products are adenosine 3',5'-bisphosphate and estrone 3-sulfate.

The enzyme also catalyzes the same reaction for estradiol, with estradiol sulfate as the product.

Types

Two enzymes have been identified that together are thought to represent estrone sulfotransferase (EST):^[1][2]

• SULT1A1 (catalyzes the reactions estradiol to estradiol sulfate and, to a lesser extent than SULT1E1, estrone to estrone sulfate)
• SULT1E1 (catalyzes the reactions estrone to estrone sulfate and estradiol to estradiol sulfate)

Function

Structure

As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes 1AQU, 1AQY, 1BO6, 1G3M, and 1HY3.

Names

The systematic name of this enzyme class is 3'-phosphoadenylyl-sulfate:estrone 3-sulfotransferase. Other names in common use include 3'-phosphoadenylyl sulfate-estrone 3-sulfotransferase, estrogen sulfotransferase, estrogen sulphotransferase, oestrogen sulphotransferase, and 3'-phosphoadenylylsulfate:oestrone sulfotransferase.