Sequence Similarity : Non-homologous sequences (<30%) SEQUENCE SIMILARITY (%) 4i1uA 4i1uB 5izsA 4i1uA 100 99 2 4i1uB 99 100 2 5izsA 20 11 100 FOLD SIMILARITY (Z-SCORE) 4i1uA 4i1uB 5izsA 4i1uA 36.9 33.4 2.6 4i1uB 33.4 36.8 2.6 5izsA 0 0 13.9