Sequence Similarity : Non-homologous sequences (<30%) SEQUENCE SIMILARITY (%) 3qt2C 3qt2D 4extA 4extC 3qt2C 100 93 34 18 3qt2D 93 100 33 18 4extA 34 33 100 41 4extC 0 0 11 100 FOLD SIMILARITY (Z-SCORE) 3qt2C 3qt2D 4extA 4extC 3qt2C 18.8 15.1 2.1 0.5 3qt2D 15.1 18.3 2.2 0.5 4extA 2.1 2.2 23.1 1.3 4extC 0 0 0 37.6