Proteorhodopsin insights into the molecular mechanism of vectorial proton transport

Bacterial proton pumps, proteorhodopsins (PRs), are a major group of light-driven membrane proteins found in marine bacteria. They are functionally and structurally distinct from archaeal and eukaryotic proton pumps. To elucidate the proton transfer mechanism by PRs and understand the differences to nonbacterial pumps on a molecular level, high-resolution structures of PRs' functional states are needed. In this work, we have determined atomic-resolution structures of MAR, a PR from marine actinobacteria, in various functional states, notably the challenging late O intermediate state. These data and information from recent atomic-resolution structures on an archaeal outward proton pump bacteriorhodopsin and bacterial inward proton pump xenorhodopsin allow for deducing key universal elements for light-driven proton pumping. First, long hydrogen-bonded chains characterize proton pathways. Second, short hydrogen bonds allow proton storage and inhibit their backflow. Last, the retinal Schiff base is the active proton donor and acceptor to and from hydrogen-bonded chains.

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Publication Details

Journal
Science Advances
Published
2025-04-16
DOI
https://doi.org/10.1126/sciadv.adu5303
Citations
3
Primary Topic
Photoreceptor and optogenetics research
Type
article
Field-Weighted Citation Impact
2.73
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article

Proteorhodopsin insights into the molecular mechanism of vectorial proton transport

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3 citations
Science Advances
Photoreceptor and optogenetics research
2.73
article

Proteorhodopsin insights into the molecular mechanism of vectorial proton transport

Alexey Alekseev, Ivan Gushchin, Roman Astashkin, Rohit Ghai, Kirill Kovalev, Dmitrii Zabelskii, Tatyana I. Rokitskaya, Fedor Tsybrov, Valentin Gordeliy, Nicolas Caramello, Valentin Borshchevskiy, Yury L. Ryzhykau, Vitaly Shevchenko, D. D. Kuklina, Gleb Bourenkov, Jacqueline Cherfils, Mahel Zeghouf, Yuri N. Antonenko, Francisco Rodríguez‐Valera, Vitaly Polovinkin, Siarhei Bukhalovich, Sergey Bukhdruker, Dmitry Bratanov, Andrey Rogachev, Maksim Rulev, Ernst Bamberg, Igor Chizhov, Ekaterina Round, Martin Engelhard, Chavdar Stoev, Anatoly Mikhaylov
article en
3 citations

Abstract

Bacterial proton pumps, proteorhodopsins (PRs), are a major group of light-driven membrane proteins found in marine bacteria. They are functionally and structurally distinct from archaeal and eukaryotic proton pumps. To elucidate the proton transfer mechanism by PRs and understand the differences to nonbacterial pumps on a molecular level, high-resolution structures of PRs' functional states are needed. In this work, we have determined atomic-resolution structures of MAR, a PR from marine actinobacteria, in various functional states, notably the challenging late O intermediate state. These data and information from recent atomic-resolution structures on an archaeal outward proton pump bacteriorhodopsin and bacterial inward proton pump xenorhodopsin allow for deducing key universal elements for light-driven proton pumping. First, long hydrogen-bonded chains characterize proton pathways. Second, short hydrogen bonds allow proton storage and inhibit their backflow. Last, the retinal Schiff base is the active proton donor and acceptor to and from hydrogen-bonded chains.

Science AdvancesVol. 11(16)
Universitat de Miguel Hernández d'Elx (ES), Uppsala University (SE), Centre National de la Recherche Scientifique (FR), Moscow Institute of Physics and Technology (RU), Universität Hamburg (DE), Lomonosov Moscow State University (RU), Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR), Université Paris-Saclay (FR), CEA Grenoble (FR), Joint Institute for Nuclear Research (RU), Medizinische Hochschule Hannover (DE), Extreme Light Infrastructure Beamlines (CZ), Institute of Cytology (RU), Max Planck Institute of Biophysics (DE), Max Planck Institute of Molecular Physiology (DE), European Molecular Biology Laboratory (DE), Institute of Hydrobiology, Biology Centre, Academy of Sciences of the Czech Republic (CZ), Laboratoire de Biologie et Pharmacologie Appliquée (FR), Institut de Biologie Structurale (FR), Institute of Hydrobiology (UA), European Molecular Biology Laboratory (DE), Hamburg University of Technology (DE), Université Grenoble Alpes (FR), European X-Ray Free-Electron Laser (DE)
Life below water
Openalex Percentile: Top 11%
Photoreceptor and optogenetics research
2.73
DOIOpen Access PDFOpenAlex
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