Sequence Similarity : Non-homologous sequences (<30%) SEQUENCE SIMILARITY (%) 3thfA 3thfB 4ey9A 4ey9B 3thfA 100 99 0 0 3thfB 99 100 0 0 4ey9A 0 0 0 0 4ey9B 0 0 0 0 FOLD SIMILARITY (Z-SCORE) 3thfA 3thfB 4ey9A 4ey9B 3thfA 13.5 12.6 0 0 3thfB 12.6 13.5 0 0 4ey9A 0 0 0 0 4ey9B 0 0 0 0