Sequence Similarity : Non-homologous sequences (<30%) SEQUENCE SIMILARITY (%) 2ccvA 5nusA 5nusB 2ccvA 100 0 0 5nusA 4 100 4 5nusB 3 3 100 FOLD SIMILARITY (Z-SCORE) 2ccvA 5nusA 5nusB 2ccvA 21.7 0 0 5nusA 0 41.9 0 5nusB 0 0 18