Enables cholest-5-ene-3-beta,7-alpha-diol 3-beta-dehydrogenase activity. Involved in cholesterol catabolic process; liver regeneration; and regulation of cell growth. Located in intracellular membrane-bounded organelle. Human ortholog(s) of this gene implicated in congenital bile acid synthesis defect 1 and intrahepatic cholestasis. Orthologous to human HSD3B7 (hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 7). [provided by Alliance of Genome Resources, Apr 2022]