Fig. 4: Cryo-EM structures of the Zn²⁺-bound hZnT7 dimers (Zn²⁺ state 1, Zn²⁺ state 2 and Zn²⁺ state 3).

a Cartoon representations show the overall structures of two types of Zn²⁺-bound hZnT7 heterodimers named Zn²⁺ state 1 (left) and Zn²⁺ state 2 (middle), and a Zn²⁺-bound hZnT7 homodimer named Zn²⁺ state 3 (right). The side (upper) and cytosolic (lower) views are shown. The black dashed-line square indicates the region that is highlighted in Fig. 5e. b Coronal sections of the electrostatic potential surfaces of the hZnT7 dimers in Zn²⁺-unbound state, Zn²⁺ state 1, Zn²⁺ state 2 and Zn²⁺ state 3. c Electrostatic potential surface around the cytosolic cavity of the IF protomer in the Zn²⁺ state 1. Surface colors indicate Coulombic potentials (red, negative; white, neutral; blue, positive).