So we have three prime and we have five prime. So we add our ECoR, one restriction enzyme, and it cleaves. It breaks the phosphodiester, the bond here and the phosphodies, the bond here. And so we produce the following two fragments with these two sticky ends. So what do we mean by a two fold rotational symmetry? So, what we mean by that is if we take this molecule and we rotate it first about the x axis, 180 degrees, and then about the Y axis, also by 180 degrees.