Structural and evolutionary aspects of thioredoxin reductases in photosynthetic organisms.
Thioredoxins (Trxs) are small oxidoreductases that are involved in redox homeostasis and are found in large numbers in the subcellular compartments of eukaryotic plant cells, including the chloroplasts. Also present in chloroplasts are two forms of thioredoxin reductase (TR), which use either NADPH or ferredoxin as an electron donor. In other compartments, two additional TR forms also use NADPH: one is distributed in all photosynthetic organisms and is similar to prokaryotic enzymes, whereas the other is restricted to algae and is similar to mammalian selenoproteins. Here, we review current knowledge of the different forms of TRs across organisms and discuss the possible evolutionary fate of this class of enzymes, which provide an example of convergent functional evolution.
Jacquot
Jean-Pierre
JP
Interactions Arbres Microorganismes UMR 1136, IFR 110, Nancy University, BP 239, 54506 Vandoeuvre Cedex, France. jean-pierre.jacquot@scbiol.uhp-nancy.fr
Eklund
Hans
H
Rouhier
Nicolas
N
Schürmann
Peter
P
D005075:Biological Evolution; D018745:Genome, Plant; D008958:Models, Molecular; D010788:Photosynthesis; D013347:Subcellular Fractions / Q000201:enzymology; D013880:Thioredoxin-Disulfide Reductase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013879:Thioredoxins / Q000378:metabolism
D013879:Thioredoxins; D013880:Thioredoxin-Disulfide Reductase