Gene organization of SmTRα and SmTRβ. A. SmTRα . B. SmTRβ . (a) Showing exons and size of introns; Roman numerals indicate exons. (b) Showing the size of exons and their correspondence to the different protein domains. A/B: A/B domain, DBD: DNA binding domain, D: D domain (hinge region), Tτ: signature sequence of the LBD, E: E domain (LBD) after Tτ.