Enables enzyme binding activity and glucuronosyltransferase activity. Involved in several processes, including biphenyl catabolic process; cellular glucuronidation; and cellular response to lipid. Located in endoplasmic reticulum. Part of cytochrome complex. Used to study Crigler-Najjar syndrome and bilirubin metabolic disorder. Biomarker of hyperthyroidism; type 1 diabetes mellitus; and type 2 diabetes mellitus. Human ortholog(s) of this gene implicated in several diseases, including bilirubin metabolic disorder (multiple); cholecystolithiasis; cholelithiasis; female reproductive organ cancer (multiple); and hepatitis B. Orthologous to human UGT1A1 (UDP glucuronosyltransferase family 1 member A1). [provided by Alliance of Genome Resources, Apr 2022]