Sulfotransferase enzymes catalyze the sulfate conjugation of many hormones, neurotransmitters, drugs, and xenobiotic compounds. These cytosolic enzymes are different in their tissue distributions and substrate specificities. The gene structure (number and length of exons) is similar among family members. This gene encodes a phenol sulfotransferase with thermolabile enzyme activity. Four sulfotransferase genes are located on the p arm of chromosome 16; this gene and SULT1A4 arose from a segmental duplication. This gene is the most centromeric of the four sulfotransferase genes. Read-through transcription exists between this gene and the upstream SLX1A (SLX1 structure-specific endonuclease subunit homolog A) gene that encodes a protein containing GIY-YIG domains.