(A) Cartoon diagrams of the high molecular weight sweet potato TRAcP template structure, 1XZW, the low molecular weight human TRAcP (Acp5), 1WAR, and the query sequence, Hsa _aTRACP. Secondary structure elements not shared between the known structures and Hsa _aTRACP model are colored magenta. The Fe(III) Fe(II) atoms in the active site are represented as spheres. (B) Comparison of topologies for the low molecular weight human TRAcP and Hsa _aTRACP. Secondary structure elements that are common to both proteins are colored yellow (for β-strands) and red for (α-helices). Secondary structure regions that are only observed in human TRAcP are colored blue. For Hsa _aTRAcP the regions of secondary structureare S1(residues 49–51), H1 (67–74), S2(85–87), H2(102–110), S3(121–122), H3(127–130), H4(141–144), S5(151–155), S6(158–162), H6(180–191), S7(199–203), H7(225–238), S8(242–245), S9(256–258) and S10(280–284). For human TRAcP (Hsa _TRAcP; see also Fig. 1) the regions of secondary structure are S1(5–10), H1(24–39), S2(44–47), H2(64–68), S3(83–85), H3(91–93), H4(96–104), S4(109–110), S5(116–121), S6(128–133), H5(136–145), H6(157–173), S7(178–182), H7(197–209), S8(214–217), S9(223–227), S10(233–237), H8(250–252), S11(258–262), S12 (270–276), S13 (280–287) and S14(292–299).