High-pH structure of EmrE reveals the mechanism of proton-coupled substrate transport
<jats:title>Abstract</jats:title><jats:p>The homo-dimeric bacterial membrane protein EmrE effluxes polyaromatic cationic substrates in a proton-coupled manner to cause multidrug resistance. We recently determined the structure of substrate-bound EmrE in phospholipid bilayers by mea...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Springer Science and Business Media LLC
2022
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| Online Access: | https://hdl.handle.net/1721.1/141081 |
| _version_ | 1811073316636590080 |
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| author | Shcherbakov, Alexander A Spreacker, Peyton J Dregni, Aurelio J Henzler-Wildman, Katherine A Hong, Mei |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Shcherbakov, Alexander A Spreacker, Peyton J Dregni, Aurelio J Henzler-Wildman, Katherine A Hong, Mei |
| author_sort | Shcherbakov, Alexander A |
| collection | MIT |
| description | <jats:title>Abstract</jats:title><jats:p>The homo-dimeric bacterial membrane protein EmrE effluxes polyaromatic cationic substrates in a proton-coupled manner to cause multidrug resistance. We recently determined the structure of substrate-bound EmrE in phospholipid bilayers by measuring hundreds of protein-ligand H<jats:sup>N</jats:sup>–F distances for a fluorinated substrate, 4-fluoro-tetraphenylphosphonium (F<jats:sub>4</jats:sub>-TPP<jats:sup>+</jats:sup>), using solid-state NMR. This structure was solved at low pH where one of the two proton-binding Glu14 residues is protonated. Here, to understand how substrate transport depends on pH, we determine the structure of the EmrE-TPP complex at high pH, where both Glu14 residues are deprotonated. The high-pH complex exhibits an elongated and hydrated binding pocket in which the substrate is similarly exposed to the two sides of the membrane. In contrast, the low-pH complex asymmetrically exposes the substrate to one side of the membrane. These pH-dependent EmrE conformations provide detailed insights into the alternating-access model, and suggest that the high-pH conformation may facilitate proton binding in the presence of the substrate, thus accelerating the conformational change of EmrE to export the substrate.</jats:p> |
| first_indexed | 2024-09-23T09:30:51Z |
| format | Article |
| id | mit-1721.1/141081 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T09:30:51Z |
| publishDate | 2022 |
| publisher | Springer Science and Business Media LLC |
| record_format | dspace |
| spelling | mit-1721.1/1410812023-04-14T18:26:43Z High-pH structure of EmrE reveals the mechanism of proton-coupled substrate transport Shcherbakov, Alexander A Spreacker, Peyton J Dregni, Aurelio J Henzler-Wildman, Katherine A Hong, Mei Massachusetts Institute of Technology. Department of Chemistry <jats:title>Abstract</jats:title><jats:p>The homo-dimeric bacterial membrane protein EmrE effluxes polyaromatic cationic substrates in a proton-coupled manner to cause multidrug resistance. We recently determined the structure of substrate-bound EmrE in phospholipid bilayers by measuring hundreds of protein-ligand H<jats:sup>N</jats:sup>–F distances for a fluorinated substrate, 4-fluoro-tetraphenylphosphonium (F<jats:sub>4</jats:sub>-TPP<jats:sup>+</jats:sup>), using solid-state NMR. This structure was solved at low pH where one of the two proton-binding Glu14 residues is protonated. Here, to understand how substrate transport depends on pH, we determine the structure of the EmrE-TPP complex at high pH, where both Glu14 residues are deprotonated. The high-pH complex exhibits an elongated and hydrated binding pocket in which the substrate is similarly exposed to the two sides of the membrane. In contrast, the low-pH complex asymmetrically exposes the substrate to one side of the membrane. These pH-dependent EmrE conformations provide detailed insights into the alternating-access model, and suggest that the high-pH conformation may facilitate proton binding in the presence of the substrate, thus accelerating the conformational change of EmrE to export the substrate.</jats:p> 2022-03-09T14:56:29Z 2022-03-09T14:56:29Z 2022-12 2022-03-09T14:53:54Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/141081 Shcherbakov, Alexander A, Spreacker, Peyton J, Dregni, Aurelio J, Henzler-Wildman, Katherine A and Hong, Mei. 2022. "High-pH structure of EmrE reveals the mechanism of proton-coupled substrate transport." Nature Communications, 13 (1). en 10.1038/s41467-022-28556-6 Nature Communications Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf Springer Science and Business Media LLC Nature |
| spellingShingle | Shcherbakov, Alexander A Spreacker, Peyton J Dregni, Aurelio J Henzler-Wildman, Katherine A Hong, Mei High-pH structure of EmrE reveals the mechanism of proton-coupled substrate transport |
| title | High-pH structure of EmrE reveals the mechanism of proton-coupled substrate transport |
| title_full | High-pH structure of EmrE reveals the mechanism of proton-coupled substrate transport |
| title_fullStr | High-pH structure of EmrE reveals the mechanism of proton-coupled substrate transport |
| title_full_unstemmed | High-pH structure of EmrE reveals the mechanism of proton-coupled substrate transport |
| title_short | High-pH structure of EmrE reveals the mechanism of proton-coupled substrate transport |
| title_sort | high ph structure of emre reveals the mechanism of proton coupled substrate transport |
| url | https://hdl.handle.net/1721.1/141081 |
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