Esterification, concomitant with transport, of endogenous long-chain fatty acids into metabolically active CoA thioesters for subsequent degradation or incorporation into phospholipids. Plays an important role in the determination of viability in the stationary phase. a long-chain fatty acid + ATP + CoA = a long-chain fatty acyl-CoA + AMP + diphosphate The FACS motif is required for catalytic activity and substrate specificity. Belongs to the ATP-dependent AMP-binding enzyme family.