Pyruvate:ferredoxin oxidoreductase and low abundant ferredoxins support aerobic photomixotrophic growth in cyanobacteria
Pyruvate:ferredoxin oxidoreductase and low abundant ferredoxins support aerobic photomixotrophic growth in cyanobacteria
Abstract The decarboxylation of pyruvate is a central reaction in the carbon metabolism of all organisms. Both the pyruvate:ferredoxin oxidoreductase (PFOR) and the pyruvate dehydrogenase (PDH) complex catalyze this reaction. Whereas PFOR reduces ferredoxin, the PDH complex utilizes NAD+. Anaerobes rely on PFOR, which was replaced during evolution by the PDH complex found in aerobes. Cyanobacteria possess both. Our data challenge the view that PFOR is exclusively utilized for fermentation. Instead, we show, that the cyanobacterial PFOR is stable in the presence of oxygen in vitro and is required for optimal photomixotrophic growth under aerobic conditions while the PDH complex is inactivated under the same conditions. We found that cells rely on a general shift from utilizing NAD(H)-dependent to ferredoxin-dependent enzymes under these conditions. The utilization of ferredoxins instead of NAD(H) saves a greater share of the Gibbs free energy, instead of wasting it as heat. This obviously simultaneously decelerates metabolic reactions as they operate closer to their thermodynamic equilibrium. It is common thought that during evolution, ferredoxins were replaced by NAD(P)H due to their higher stability in an oxidizing atmosphere. However, utilization of NAD(P)H could also have been favored due to a higher competitiveness because of an accelerated metabolism.
Spengler Katharina、Appel Jens、Barske Thomas、Timm Stefan、Battchikova Natalia、Hagemann Martin、Chen Xi、Gutekunst Kirstin、Boehm Marko、Wang Yingying、Terberger Karoline
Department of Biology, Botanical Institute, Christian-Albrechts-UniversityDepartment of Biology, Botanical Institute, Christian-Albrechts-University||Department of Molecular Plant Physiology, Bioenergetics in Photoautotrophs, University of KasselPlant Physiology Department, University of RostockPlant Physiology Department, University of RostockDepartment of Biochemistry, Molecular Plant Biology, University of TurkuPlant Physiology Department, University of RostockDepartment of Biology, Botanical Institute, Christian-Albrechts-UniversityDepartment of Biology, Botanical Institute, Christian-Albrechts-University||Department of Molecular Plant Physiology, Bioenergetics in Photoautotrophs, University of KasselDepartment of Biology, Botanical Institute, Christian-Albrechts-University||Department of Molecular Plant Physiology, Bioenergetics in Photoautotrophs, University of KasselDepartment of Biology, Botanical Institute, Christian-Albrechts-UniversityDepartment of Biology, Botanical Institute, Christian-Albrechts-University
生物化学分子生物学细胞生物学
cyanobacteriaferredoxinGOGATpyruvate dehydrogenase
Spengler Katharina,Appel Jens,Barske Thomas,Timm Stefan,Battchikova Natalia,Hagemann Martin,Chen Xi,Gutekunst Kirstin,Boehm Marko,Wang Yingying,Terberger Karoline.Pyruvate:ferredoxin oxidoreductase and low abundant ferredoxins support aerobic photomixotrophic growth in cyanobacteria[EB/OL].(2025-03-28)[2025-04-26].https://www.biorxiv.org/content/10.1101/2021.08.27.457892.点此复制
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