octadecanoyl-AMP + holo-[(hydroxy)phthioceranic acid synthase] => octadecanoyl-[(hydroxy)phthioceranic acid synthase] + AMP + H(+)
octadecanoyl-amp + holo-[(hydroxy)phthioceranic acid synthase] => octadecanoyl-[(hydroxy)phthioceranic acid synthase] + amp + h(+)