Catalyzes the synthesis of acetyl-CoA from short-chain fatty acids (PubMed:28003429). Propionate is the preferred substrate but can also utilize acetate and butyrate with a much lower affinity (PubMed:28003429). acetate + ATP + CoA = acetyl-CoA + AMP + diphosphate ATP + CoA + propanoate = AMP + diphosphate + propanoyl-CoA ATP + butanoate + CoA = AMP + butanoyl-CoA + diphosphate Expressed in a wide range of tissues, with the highest levels observed in the liver followed by kidney. Expression is up-regulated by fasting. Belongs to the ATP-dependent AMP-binding enzyme family.