Sequence Similarity : Non-homologous sequences (<30%) SEQUENCE SIMILARITY (%) 4grxA 4xvvA 4xvvB 4grxA 100 0 0 4xvvA 21 100 97 4xvvB 12 97 100 FOLD SIMILARITY (Z-SCORE) 4grxA 4xvvA 4xvvB 4grxA 68.4 0 0 4xvvA 0 19.1 15.8 4xvvB 0 15.8 18.1