Redox-coupled proton pumping drives carbon concentration in the photosynthetic complex I
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, cyano...
Gespeichert in:
Veröffentlicht in: | Nature communications 2020-01, Vol.11 (1), p.494-494, Article 494 |
---|---|
Hauptverfasser: | , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | 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.
Cyanobacteria evolved carbon-concentration mechanisms to enhance the efficiency of photosynthetic CO
2
fixation, but the molecular principles have remained unknown. Here authors use cryo-EM to reveal how modular adaptations enabled the photosynthetic complex I from the cyanobacterium Thermosynechococcus elongatus to concentrate CO
2
. |
---|---|
ISSN: | 2041-1723 2041-1723 |
DOI: | 10.1038/s41467-020-14347-4 |