Mapping epitopes onto the trans TPO dimer.

<p><b>(A)</b> Epitopes and residues identified in various studies as constituting immunodominant regions IDR-A (blue) and IDR-B (pink); <b>(B)</b> Membrane-facing side of MPO-like domain; <b>(C)</b> Close-up shows that much of the two immunodominant regions are on the membrane-facing surface of the MPO-like domain, particularly IDR-B; <b>(D)</b> Lumen-facing side of TPO. Hemes are shown in orange.</p>