Ferredoxin:thioredoxin reductase (FTR) links the regulation of oxygenic photosynthesis to deeply rooted bacteria

• Published in: Planta 2013-02, Vol.237 (2), p.619-635
• Main Authors: Balsera, Monica, Uberegui, Estefania, Susanti, Dwi, Schmitz, Ruth A., Mukhopadhyay, Biswarup, Schürmann, Peter, Buchanan, Bob B.
• Format: Article
• Language: English
• Subjects: Agriculture; Amino Acid Sequence; Archaea; Bacteria; Bacteria - classification; Bacteria - enzymology; Bacteria - genetics; Bacteria - radiation effects; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biomedical and Life Sciences; Carbon Dioxide - metabolism; Carbon dioxide fixation; Chloroplast Proteins - genetics; Chloroplast Proteins - metabolism; Chloroplasts; Chloroplasts - enzymology; Chloroplasts - genetics; Cyanobacteria; Databases, Genetic; Ecology; Enzymes; Evolution; Evolution, Molecular; Ferredoxins - metabolism; Forestry; Gene expression regulation; Genomes; Iron-Sulfur Proteins - genetics; Iron-Sulfur Proteins - metabolism; Life Sciences; Light; Molecular Sequence Data; Original Article; Oxidation-Reduction; Oxidoreductases - genetics; Oxidoreductases - metabolism; Oxygen - metabolism; Phosphotransferases (Alcohol Group Acceptor) - genetics; Phosphotransferases (Alcohol Group Acceptor) - metabolism; Photosynthesis; Phylogeny; Plant Sciences; Plants; Plants - classification; Plants - enzymology; Plants - genetics; Plants - radiation effects; Sequence Alignment; Thioredoxin
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-012-1803-y

Uncovered in studies on photosynthesis 35 years ago, redox regulation has been extended to all types of living cells. We understand a great deal about the occurrence, function, and mechanism of action of this mode of regulation, but we know little about its origin and its evolution. To help fill this gap, we have taken advantage of available genome sequences that make it possible to trace the phylogenetic roots of members of the system that was originally described for chloroplasts—ferredoxin, ferredoxin:thioredoxin reductase (FTR), and thioredoxin as well as target enzymes. The results suggest that: (1) the catalytic subunit, FTRc, originated in deeply rooted microaerophilic, chemoautotrophic bacteria where it appears to function in regulating CO2 fixation by the reverse citric acid cycle; (2) FTRc was incorporated into oxygenic photosynthetic organisms without significant structural change except for addition of a variable subunit (FTRv) seemingly to protect the Fe—S cluster against oxygen; (3) new Trxs and target enzymes were systematically added as evolution proceeded from bacteria through the different types of oxygenic photosynthetic organisms; (4) an oxygenic type of regulation preceded classical light—dark regulation in the regulation of enzymes of CO2 fixation by the Calvin—Benson cycle; (5) FTR is not universally present in oxygenic photosynthetic organisms, and in certain early representatives is seemingly functionally replaced by NADP-thioredoxin reductase; and (6) FTRc underwent structural diversification to meet the ecological needs of a variety of bacteria and archaea.