Cryo-EM reveals distinct conformations of E. coli ATP synthase on exposure to ATP

Authors

Meghna Sobti, Victor Chang Cardiac Research Institute, University of New South Wales
Robert Ishmukhametov, University of Oxford
James C. Bouwer, University of WollongongFollow
Anita Ayer, Victor Chang Cardiac Research Institute, University of New South Wales
Cacang Suarna, Victor Chang Cardiac Research Institute
Nicola Smith, Victor Chang Cardiac Research Institute, University of New South Wales
Mary Christie, Victor Chang Cardiac Research Institute, University of New South Wales
Roland Stocker, Victor Chang Cardiac Research Institute, University of New South Wales
Thomas Duncan, SUNY Upstate Medical University
Alastair G. Stewart, Victor Chang Cardiac Research Institute, University of New South Wales

RIS ID

134786

Publication Details

Sobti, M., Ishmukhametov, R., Bouwer, J. C., Ayer, A., Suarna, C., Smith, N. J., Christie, M., Stocker, R., Duncan, T. M. & Stewart, A. G. (2019). Cryo-EM reveals distinct conformations of E. coli ATP synthase on exposure to ATP. eLIFE, 8 e43864-1-e43864-16.

Abstract

ATP synthase produces the majority of cellular energy in most cells. We have previously reported cryo-EM maps of autoinhibited E. coli ATP synthase imaged without addition of nucleotide (Sobti et al. 2016), indicating that the subunit ε engages the α, β and γ subunits to lock the enzyme and prevent functional rotation. Here we present multiple cryo-EM reconstructions of the enzyme frozen after the addition of MgATP to identify the changes that occur when this ε inhibition is removed. The maps generated show that, after exposure to MgATP, E. coli ATP synthase adopts a different conformation with a catalytic subunit changing conformation substantially and the ε C-terminal domain transitioning via an intermediate 'half-up' state to a condensed 'down' state. This work provides direct evidence for unique conformational states that occur in E. coli ATP synthase when ATP binding prevents the ε C-terminal domain from entering the inhibitory 'up' state.