Catalyzes the conversion of fatty acids such as long-chain and very long-chain fatty acids to their active form acyl-CoAs for both synthesis of cellular lipids, and degradation via beta-oxidation. Can activate diverse saturated, monosaturated and polyunsaturated fatty acids. a long-chain fatty acid + ATP + CoA = a long-chain fatty acyl-CoA + AMP + diphosphate (E)-hexadec-2-enoate + ATP + CoA = (2E)-hexadecenoyl-CoA + AMP + diphosphate ATP + CoA + hexadecanoate = AMP + diphosphate + hexadecanoyl-CoA Present in testis, at a lower level in brain, and at a very low level in ovary. Not detected in other tissues. tested. Present in Leydig cells of the adult testis and to a lesser degree in the seminiferous tubules in spermatogonia and Sertoli cells (at protein level). Down-regulated by gonadotropin. Belongs to the ATP-dependent AMP-binding enzyme family. Bubblegum subfamily.