Structure and mechanism of the Mrp complex, an ancient cation/proton antiporter
Multiple resistance and pH adaptation (Mrp) antiporters are multi-subunit Na+ (or K+)/H+ exchangers representing an ancestor of many essential redox-driven proton pumps, such as respiratory complex I. The mechanism of coupling between ion or electron transfer and proton translocation in this large p...
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| Format: | Article |
| Language: | English |
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eLife Sciences Publications Ltd
2020-07-01
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| Series: | eLife |
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| Online Access: | https://elifesciences.org/articles/59407 |
| _version_ | 1797991946609754112 |
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| author | Julia Steiner Leonid Sazanov |
| author_facet | Julia Steiner Leonid Sazanov |
| author_sort | Julia Steiner |
| collection | DOAJ |
| description | Multiple resistance and pH adaptation (Mrp) antiporters are multi-subunit Na+ (or K+)/H+ exchangers representing an ancestor of many essential redox-driven proton pumps, such as respiratory complex I. The mechanism of coupling between ion or electron transfer and proton translocation in this large protein family is unknown. Here, we present the structure of the Mrp complex from Anoxybacillus flavithermus solved by cryo-EM at 3.0 Å resolution. It is a dimer of seven-subunit protomers with 50 trans-membrane helices each. Surface charge distribution within each monomer is remarkably asymmetric, revealing probable proton and sodium translocation pathways. On the basis of the structure we propose a mechanism where the coupling between sodium and proton translocation is facilitated by a series of electrostatic interactions between a cation and key charged residues. This mechanism is likely to be applicable to the entire family of redox proton pumps, where electron transfer to substrates replaces cation movements. |
| first_indexed | 2024-04-11T09:00:17Z |
| format | Article |
| id | doaj.art-226ffc8cd5514600b8e23e2605998ce4 |
| institution | Directory Open Access Journal |
| issn | 2050-084X |
| language | English |
| last_indexed | 2024-04-11T09:00:17Z |
| publishDate | 2020-07-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj.art-226ffc8cd5514600b8e23e2605998ce42022-12-22T04:32:48ZengeLife Sciences Publications LtdeLife2050-084X2020-07-01910.7554/eLife.59407Structure and mechanism of the Mrp complex, an ancient cation/proton antiporterJulia Steiner0Leonid Sazanov1https://orcid.org/0000-0002-0977-7989Institute of Science and Technology Austria, Klosterneuburg, AustriaInstitute of Science and Technology Austria, Klosterneuburg, AustriaMultiple resistance and pH adaptation (Mrp) antiporters are multi-subunit Na+ (or K+)/H+ exchangers representing an ancestor of many essential redox-driven proton pumps, such as respiratory complex I. The mechanism of coupling between ion or electron transfer and proton translocation in this large protein family is unknown. Here, we present the structure of the Mrp complex from Anoxybacillus flavithermus solved by cryo-EM at 3.0 Å resolution. It is a dimer of seven-subunit protomers with 50 trans-membrane helices each. Surface charge distribution within each monomer is remarkably asymmetric, revealing probable proton and sodium translocation pathways. On the basis of the structure we propose a mechanism where the coupling between sodium and proton translocation is facilitated by a series of electrostatic interactions between a cation and key charged residues. This mechanism is likely to be applicable to the entire family of redox proton pumps, where electron transfer to substrates replaces cation movements.https://elifesciences.org/articles/59407anoxybacillus flavithermusmembrane transportantiporterrespiratory complex Iproton pump |
| spellingShingle | Julia Steiner Leonid Sazanov Structure and mechanism of the Mrp complex, an ancient cation/proton antiporter eLife anoxybacillus flavithermus membrane transport antiporter respiratory complex I proton pump |
| title | Structure and mechanism of the Mrp complex, an ancient cation/proton antiporter |
| title_full | Structure and mechanism of the Mrp complex, an ancient cation/proton antiporter |
| title_fullStr | Structure and mechanism of the Mrp complex, an ancient cation/proton antiporter |
| title_full_unstemmed | Structure and mechanism of the Mrp complex, an ancient cation/proton antiporter |
| title_short | Structure and mechanism of the Mrp complex, an ancient cation/proton antiporter |
| title_sort | structure and mechanism of the mrp complex an ancient cation proton antiporter |
| topic | anoxybacillus flavithermus membrane transport antiporter respiratory complex I proton pump |
| url | https://elifesciences.org/articles/59407 |
| work_keys_str_mv | AT juliasteiner structureandmechanismofthemrpcomplexanancientcationprotonantiporter AT leonidsazanov structureandmechanismofthemrpcomplexanancientcationprotonantiporter |