Figure 7: Structure of the P_i-bound V₁ complex (1_PiV₁).

(a) Side view. (b) Top views of the C-terminal domain (transparent surface in a) from the cytoplasmic side in which the ‘bound’ form is superimposed onto that of eV₁ (grey). (c) Magnified nucleotide-binding site of the ‘tight’ form in 1_PiV₁, as in Fig. 4a. The |Fo|-|Fc| maps calculated without P_i:Mg²⁺ at the binding pockets contoured at 4.0 sigma are shown in red (negative) and green (positive), respectively. (d,e) The viewing position, colours and representations of the binding sites correspond to those in the right panel of c. The ‘tight’ form (c) in 1_PiV₁, in which the Eh-A residues (67–593) are superimposed onto the same residues of the ‘tight’ form (shown in transparent grey) in eV₁ (d) and bV₁ (e), as in Fig. 4c. The bound P_i molecule is depicted in stick format and coloured orange.