Structural changes in the γ and ε subunits of the Escherichia coli F¹F₀-type ATPase during energy coupling

Structural changes in the Escherichia cou ATP synthase (ECF₁F₀) occur as part of catalysis, cooperativity and energy coupling within the complex. The γ and ε subunits, two major components of the stalk that links the F¹ and F₀ parts, are intimately involved in conformational coupling that links catalytic site events in the F₁ part with proton pumping through the membrane embedded F₀ sector. Movements of the γ subunit have been observed by electron microscopy, and by cross-linking and fluorescence studies in which reagents are bound to Cys residues introduced at selected sites by mutagenesis. Conformational changes and shifts of the ε subunit related to changes in nucleotide occupancy of catalytic sites have been followed by similar approaches.