Figure 4
The interactions of DBDs with response elements. Shown are structures of NR DBD homodimers, heterodimers, and monomers on response elements consisting of direct repeats (DRs), palindromes (Pal), and single half sites. The spacer size has a dramatic effect on the relative rotation and displacement of the two DBDs, fostering their productive dimerization contacts on the correctly spaced element, but blocking their dimerization when the spacing size is incorrect. Monomeric NRs use the same consensus half sites but rely on the immediate flanking base pairs upstream of their half site for response element discrimination.
