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

Autor: Meghna Sobti, Robert Ishmukhametov, James C Bouwer, Anita Ayer, Cacang Suarna, Nicola J Smith, Mary Christie, Roland Stocker, Thomas M Duncan, Alastair G Stewart
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: eLife, Vol 8 (2019)
Druh dokumentu: article
ISSN: 2050-084X
DOI: 10.7554/eLife.43864
Popis: 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.
Databáze: Directory of Open Access Journals