Sulfotransferase that utilizes 3'-phospho-5'-adenylyl sulfate (PAPS) as sulfonate donor. Has sulfotransferase activity towards various substrates, such as bile acids, thyroid hormones and toward xenobiotic compounds such as chloro phenols and hydroxypyrenes. Lithocholic acid appears to be the best substrate among the endogenous compounds tested and 3,3',5,5'-tetrachloro-4,4'-biphenyldiol shows the highest specific activity among the xenobiotic compounds. Exhibits weak sulphating activity and only toward chloro phenols (pentachlorophenol and 3,3',5,5'-tetrachloro-4,4'-biphenyldiol). 3'-phosphoadenylyl sulfate + an alcohol = adenosine 3',5'-bisphosphate + an alkyl sulfate + H(+) 3'-phosphoadenylyl sulfate + a phenol = adenosine 3',5'-bisphosphate + an aryl sulfate + H(+) 3'-phosphoadenylyl sulfate + lithocholate = adenosine 3',5'-bisphosphate + H(+) + lithocholate sulfate Contains alternative exons 7 (7b) and 8 (8b) which may generate three possible splice variants containing sequences corresponding respectively to exons 7a and 8a (SULT1C3a), exons 7a and 8b (SULT1C3c) and exons 7b and 8b (SULT1C3d). So far, it is not known which isoforms are expressed. Not detectable in any of the tissues tested. Expressed in the small intestine. SULT1C3 gene appears to be present only in humans and other primates. Belongs to the sulfotransferase 1 family.