Figure 3

Divergence on position 154 from set 2 and position 157 from set 3 are correlated with distortions on the HRE global topology. A and B are, respectively the hRXRα/hTRβ:DR4 heterodimer and the hTRβ homodimer in an everted palindrome, both presenting short chain glycine residues at positions 154 and 157 (volumes shown as van der Walls transparent spheres) and an straight axis at the DNA topology. In C, the bulkier alanine side chain at position 157 from hER is well fitted to the ERE bent axis. In D, the higher distortion on the GRE axis (due the central AA kink) is accompanied by the bulkier G154S and G157V substitutions, and also a reduction on the chain at the 188 position with a Q-P exchange (asterisk). It can be noted the packing of the bulky V157 against the fourth anti-sense thimidine at the axis kink.