CONFORMATIONALLY LOOSE. “Intrinsically disordered segments lack a unique three-dimensional structure, either entirely or in parts, when expressed as autonomous units, and it is assumed that they sample a variety of conformations that are in equilibrium under physiological conditions.”
http://www.biochemj.org/content/454/3/361?sa=X&ved=0CDkQ9QEwEWoVChMIzdjAo5n2xgIVovRyCh0HSAum