Download MendeleyRedox-coupled proton pumping drives carbon concentration in the photosynthetic complex I.
Schuller, J.M., Saura, P., Thiemann, J., Schuller, S.K., Gamiz-Hernandez, A.P., Kurisu, G., Nowaczyk, M.M., Kaila, V.R.I.(2020) Nat Commun 11: 494-494
- PubMed: 31980611
- DOI: https://doi.org/10.1038/s41467-020-14347-4
- Primary Citation of Related Structures:
6TJV - PubMed Abstract:
Photosynthetic organisms capture light energy to drive their energy metabolism, and employ the chemical reducing power to convert carbon dioxide (CO 2 ) into organic molecules. Photorespiration, however, significantly reduces the photosynthetic yields. To survive under low CO 2 concentrations, cyanobacteria evolved unique carbon-concentration mechanisms that enhance the efficiency of photosynthetic CO 2 fixation, for which the molecular principles have remained unknown. We show here how modular adaptations enabled the cyanobacterial photosynthetic complex I to concentrate CO 2 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 2+ 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 2 conditions.
Organizational Affiliation:
Department of Structural Cell Biology, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany. janschu@biochem.mpg.de.
