(a) Analytical ultracentrifugation profiles of apo-TP1 (blue) and Zn-TP1 (magenta). (b) Thermal denaturation of apo-TP1 (blue), Zn-TP1 (magenta) and ApoCyt (grey). (c) Superposition of experimental (magenta) and designed (grey) structures of Zn-TP1 (PDB: 8SJH), and (d) close-up views of engineered interfacial residues. (e) Views of the Zn-66His3 center (Zn – grey sphere, chloride – green sphere), along with 2Fo-Fc (grey mesh, 1.0σ) and Zn-anomalous maps (blue mesh, 5.0σ). (f) Superposition of Zn-TP1 (magenta) and apo-TP1 (cyan, PDB: 8SJI) structures.