Enables bile acid transmembrane transporter activity; protein heterodimerization activity; and protein homodimerization activity. Involved in bile acid and bile salt transport. Acts upstream of or within organic substance transport. Located in basolateral plasma membrane and endoplasmic reticulum membrane. Is integral component of membrane. Part of protein-containing complex. Is expressed in midgut and small intestine. Human ortholog(s) of this gene implicated in progressive familial intrahepatic cholestasis. Orthologous to human SLC51A (solute carrier family 51 subunit alpha). [provided by Alliance of Genome Resources, Apr 2022]