A comparison between membrane-embedded, dimeric models of TPO isoform1 in two different conformations.

(A) Schematic of trans model with active site facing away from follicular membrane. Coloring as in Fig 1; (B) Cis model with active site facing towards follicular membrane; (C) perpendicular views of trans model; (D) perpendicular views of cis model. TPO represented as cartoon and space filling (subunits A and B, respectively) for clarity. Domains are coloured as follows: MPO-like domain (green), CCP-like domain (Shamrock green), EGF-like domain (cyan-blue), and TM domain (dark-blue). Catalytic heme represented as red spheres, and DMPC molecules represented as lines and coloured as CPK.