Sequence Similarity : Non-homologous sequences (<30%) SEQUENCE SIMILARITY (%) 1zs4A 4giuA 5o5lA 1zs4A 100 0 26 4giuA 0 100 78 5o5lA 0 81 100 FOLD SIMILARITY (Z-SCORE) 1zs4A 4giuA 5o5lA 1zs4A 13.4 0.9 0 4giuA 0 66.5 0 5o5lA 0 0.1 37.9