(A) Cartoon presentation of TH-domain of human TIPE3 (trTIPE3, residues 21-204). Helices are rainbow-colored with α0 in blue and α6 in red. (B) Cartoon representation of superposition of human TIPE3 (residues 21-204, shown in green) with the human TIPE2 (residues 24-184, shown in red) structures. (C) TIPE3 contains a centrally located hydrophobic cavity. (Left panel) TIPE3 is shown in green cartoon representation; amino acids with hydrophobic side chains that line the cavity are shown in orange. (Right panel) TIPE3 eletrostatic surface potential: blue, positive; red, negative. (D) TIPE3 is shown in green cartoon representation. The two long connected tubes of 2Fo-Fc electron density found in TIPE3 cavity is shown in blue mesh, contoured at 1.5σ. See also Table S1 and Figure S6.