Sequence Similarity : Homologous sequences (>30%) SEQUENCE SIMILARITY (%) 2qxxA 4revA 6cl6A 2qxxA 100 31 70 4revA 43 100 49 6cl6A 62 66 100 FOLD SIMILARITY (Z-SCORE) 2qxxA 4revA 6cl6A 2qxxA 34.9 0 0 4revA 0 26.3 1.2 6cl6A 0 0 30.2