Sequence Similarity : Non-homologous sequences (<30%) SEQUENCE SIMILARITY (%) 3kpeA 3mgnA 4usxA 3kpeA 100 11 3 3mgnA 12 100 0 4usxA 0 0 100 FOLD SIMILARITY (Z-SCORE) 3kpeA 3mgnA 4usxA 3kpeA 6.9 5.3 0 3mgnA 5 6.5 2 4usxA 0 0 21.1