Structure of a bacterial ATP synthase
- The Hospital for Sick Children, Canada
- Tokyo Institute of Technology, Japan
Abstract
ATP synthases produce ATP from ADP and inorganic phosphate with energy from a transmembrane proton motive force. Bacterial ATP synthases have been studied extensively because they are the simplest form of the enzyme and because of the relative ease of genetic manipulation of these complexes. We expressed the Bacillus PS3 ATP synthase in Eschericia coli, purified it, and imaged it by cryo-EM, allowing us to build atomic models of the complex in three rotational states. The position of subunit e shows how it is able to inhibit ATP hydrolysis while allowing ATP synthesis. The architecture of the membrane region shows how the simple bacterial ATP synthase is able to perform the same core functions as the equivalent, but more complicated, mitochondrial complex. The structures reveal the path of transmembrane proton translocation and provide a model for understanding decades of biochemical analysis interrogating the roles of specific residues in the enzyme.
Data availability
CryoEM maps have been deposited in EMDB and atomic models in PDB.
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Intact class 1Electron Microscopy Data Bank, EMD-9333.
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Intact class 2Electron Microscopy Data Bank, EMD-9334.
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Intact class 3Electron Microscopy Data Bank, EMD-9335.
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Focused Fo/stalk class 1Electron Microscopy Data Bank, EMD-9336.
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Focused Fo/stalk class 2Electron Microscopy Data Bank, EMD-9337.
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Focused Fo/stalk class 3Electron Microscopy Data Bank, EMD-9338.
Article and author information
Author details
Funding
Canadian Institutes of Health Research (MOP 81294)
- John L Rubinstein
Canada Research Chairs
- John L Rubinstein
Japan Society for the Promotion of Science (JP18H02409)
- Toshiharu Suzuki
Canada Foundation for Innovation
- John L Rubinstein
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2019, Guo et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Structure of a bacterial ATP synthase
eLife 8:e43128.
https://doi.org/10.7554/eLife.43128
Further reading
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- Biochemistry and Chemical Biology
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Liquid-liquid phase separation (LLPS) involving intrinsically disordered protein regions (IDRs) is a major physical mechanism for biological membraneless compartmentalization. The multifaceted electrostatic effects in these biomolecular condensates are exemplified here by experimental and theoretical investigations of the different salt- and ATP-dependent LLPSs of an IDR of messenger RNA-regulating protein Caprin1 and its phosphorylated variant pY-Caprin1, exhibiting, for example, reentrant behaviors in some instances but not others. Experimental data are rationalized by physical modeling using analytical theory, molecular dynamics, and polymer field-theoretic simulations, indicating that interchain ion bridges enhance LLPS of polyelectrolytes such as Caprin1 and the high valency of ATP-magnesium is a significant factor for its colocalization with the condensed phases, as similar trends are observed for other IDRs. The electrostatic nature of these features complements ATP’s involvement in π-related interactions and as an amphiphilic hydrotrope, underscoring a general role of biomolecular condensates in modulating ion concentrations and its functional ramifications.
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