Sequence Similarity : Non-homologous sequences (<30%) SEQUENCE SIMILARITY (%) 1useA 3tsiA 3tsiD 1useA 100 8 5 3tsiA 3 100 23 3tsiD 5 8 100 FOLD SIMILARITY (Z-SCORE) 1useA 3tsiA 3tsiD 1useA 6.1 4 4 3tsiA 4.3 7.1 4.8 3tsiD 4 5.1 7.1