Involved in cholate catabolism (PubMed:23024343, PubMed:24244004). Catalyzes the ATP-dependent formation of CoA thioesters of steroids with isopropanoyl side chains, likely occurring as degradation intermediates (PubMed:23024343, PubMed:24244004). Can use 4-BNC, HSBNC and HIDP as substrate (PubMed:23024343, PubMed:24244004). 3-oxochol-4-en-22-oate + ATP + CoA = 3-oxochol-4-en-22-oyl-CoA + AMP + diphosphate 3-hydroxy-9-oxo-9,10-seco-chola-1,3,5-trien-22-oate + ATP + CoA = 3-hydroxy-9-oxo-9,10-seco-chola-1,3,5-trien-22-oyl-CoA + AMP + diphosphate kcat is 18 sec(-1) with 4-BNC as substrate. kcat is 1.4 sec(-1) with HSBNC as substrate. kcat is 60 sec(-1) with HIDP as substrate. Steroid metabolism. Up-regulated on cholate. Belongs to the ATP-dependent AMP-binding enzyme family.