Catalyzes the activation of medium/long-chain fatty acids as acyl-coenzyme A (acyl-CoA). a medium chain fatty acid + ATP + CoA = a medium-chain fatty acyl-CoA + AMP + diphosphate a long-chain fatty acid + ATP + CoA = a long-chain fatty acyl-CoA + AMP + diphosphate ATP + CoA + hexanoate = AMP + diphosphate + hexanoyl-CoA ATP + CoA + dodecanoate = AMP + diphosphate + dodecanoyl-CoA ATP + CoA + hexadecanoate = AMP + diphosphate + hexadecanoyl-CoA Lipid metabolism; fatty acid metabolism. Belongs to the ATP-dependent AMP-binding enzyme family.