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Title | Redox-coupled proton pumping drives carbon concentration in the photosynthetic complex I. |
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Journal, issue, pages | Nat Commun, Vol. 11, Issue 1, Page 494, Year 2020 |
Publish date | Jan 24, 2020 |
Authors | Jan M Schuller / Patricia Saura / Jacqueline Thiemann / Sandra K Schuller / Ana P Gamiz-Hernandez / Genji Kurisu / Marc M Nowaczyk / Ville R I Kaila / |
PubMed Abstract | Photosynthetic organisms capture light energy to drive their energy metabolism, and employ the chemical reducing power to convert carbon dioxide (CO) into organic molecules. Photorespiration, ...Photosynthetic organisms capture light energy to drive their energy metabolism, and employ the chemical reducing power to convert carbon dioxide (CO) into organic molecules. Photorespiration, however, significantly reduces the photosynthetic yields. To survive under low CO concentrations, cyanobacteria evolved unique carbon-concentration mechanisms that enhance the efficiency of photosynthetic CO fixation, for which the molecular principles have remained unknown. We show here how modular adaptations enabled the cyanobacterial photosynthetic complex I to concentrate CO using a redox-driven proton-pumping machinery. Our cryo-electron microscopy structure at 3.2 Å resolution shows a catalytic carbonic anhydrase module that harbours a Zn active site, with connectivity to proton-pumping subunits that are activated by electron transfer from photosystem I. Our findings illustrate molecular principles in the photosynthetic complex I machinery that enabled cyanobacteria to survive in drastically changing CO conditions. |
External links | Nat Commun / PubMed:31980611 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.2 Å |
Structure data | EMDB-10513, PDB-6tjv: |
Chemicals | ChemComp-DGD: ChemComp-PGT: ChemComp-SQD: ChemComp-BCR: ChemComp-CLA: ChemComp-SF4: ChemComp-ZN: ChemComp-HOH: |
Source |
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Keywords | MEMBRANE PROTEIN / carbon concentrating photosynthetic complex I / proton pump |