Esterification, concomitant with transport, of exogenous long-chain fatty acids into metabolically active CoA thioesters for subsequent degradation or incorporation into phospholipids. It may supplement intracellular myristoyl-CoA pools from exogenous myristate. Preferentially acts on C12:0-C16:0 fatty acids with myristic and pentadecanic acid (C15:0) having the highest activities (By similarity). Appears to play a role in the maintenance of cell viability during 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.