Involved in the biosynthesis of mycolic acids (By similarity). Catalyzes the activation of long-chain fatty acids as acyl-adenylates (acyl-AMP), which are then transferred to the phosphopantetheine arm of the polyketide synthase Pks13 for further chain extension (By similarity). Can use dodecanoate (C12) and tetradecanoate (C14) (PubMed:26900152). a long-chain fatty acid + ATP + holo-[ACP] = a long-chain fatty acyl-[ACP] + AMP + diphosphate ATP + dodecanoate + H(+) = diphosphate + dodecanoyl-AMP ATP + H(+) + tetradecanoate = diphosphate + tetradecanoyl-AMP The acyl-AMP ligase activity is inhibited by the alkylphosphate esters of AMP, adenosine 50-dodecylphosphate (AMPC12) and eicosyl-AMP (AMPC20). kcat is 1.51 min(-1) with dodecanoate as substrate (PubMed:26900152). kcat is 0.69 min(-1) with tetradecanoate as substrate (PubMed:26900152). Lipid metabolism; mycolic acid biosynthesis. Monomer. Belongs to the ATP-dependent AMP-binding enzyme family.