Location of the regions participating in the IDR. (A) Regions involved in the binding with aAbs are indicated on a three-dimensional diagram of the human TPO : positions 353–363 in yellow, 377–386 in red, 506–514 in green, 713–720 in blue, 599–617 in orange in the MPO-like domain, 737–740 in pink, and 766–775 in orange in the CCP-like domain. The flexibility of the hinge regions is represented by a white arrow. (B) Ribbon diagram representing the possible folding of the CCP-like domain onto the MPO-like domain. An immunodominant binding surface is virtually represented by three dotted lines and the distance (in Å) between the regions 377–387 and 713–720 is shown. The model was adjusted by using Swiss-PDB viewer 3.7b2 freeware available at http://www.expasy.ch/spdbv.