Figure 3. Recognition of auxin response elements (AuxRE) by the ARF DNA binding domain using a molecular calipers mechanism.
The structure of the AtARF1 dimerized DNA binding domain bound to the ER7 everted repeat containing two AuxREs (PDB: 4LDX; [34]) is shown. One monomer is shown as a surface rendering and the other as a ribbon diagram. The dimerization domain allows for spacing of the B3 DNA binding domain into the major groove of the DNA to interact with the AuxRE (red), leading to a suggested molecular calipers mechanism of DNA recognition by ARF proteins [34].