The graphical representations of the secondary structures for all the cases are shown in Fig. . It is observed that the loop-region, especially the 367-379 amino-acid residues of the BTB-domain shows the major difference in the structure, mainly in the Y493H. However, there is no large conformational differences are observed in between the 380 to 442 aminoacid residues except for Y493H, where the trend of secondary structure is changed around 416 to 421 amino-acid residues.