Hexameric oligomerization of mitochondrial peroxiredoxin PrxIIF and formation of an ultrahigh affinity complex with its electron donor thioredoxin Trx-o
Open Access
- 4 July 2008
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Experimental Botany
- Vol. 59 (12), 3259-3269
- https://doi.org/10.1093/jxb/ern177
Abstract
Mitochondria from plants, yeast, and animals each contain at least one peroxiredoxin (Prx) that is involved in peroxide detoxification and redox signalling. The supramolecular dynamics of atypical type II Prx targeted to the mitochondrion was addressed in pea. Microcalorimetric (ITC) titrations identified an extremely high-affinity binding between the mitochondrial PsPrxIIF and Trx-o with a KD of 126±14 pM. Binding was driven by a favourable enthalpy change (ΔH= –60.6 kcal mol−1) which was counterbalanced by unfavourable entropy changes (TΔS= –47.1 kcal mol−1). This is consistent with the occurrence of large conformational changes during binding which was abolished upon site-directed mutaganesis of the catalytic C59S and C84S. The redox-dependent interaction was confirmed by gel filtration of mitochondrial extracts and co-immunoprecipitation from extracts. The heterocomplex of PsPrxIIF and Trx-o reduced peroxide substrates more efficiently than free PsPrxIIF suggesting that Trx-o serves as an efficient and specific electron donor to PsPrxIIF in vivo. Other Trx-s tested by ITC analysis failed to interact with PsPrxIIF indicating a specific recognition of PsPrxIIF by Trx-o. PsPrxIIF exists primarily as a dimer or a hexamer depending on the redox state. In addition to the well-characterized oligomerization of classical 2-Cys Prx the results also show that atypical Prx undergo large structural reorganization with implications for protein–protein interaction and function.Keywords
This publication has 38 references indexed in Scilit:
- Thermodynamics of the Dimer−Decamer Transition of Reduced Human and Plant 2-Cys PeroxiredoxinBiochemistry, 2008
- Reconstitution of the Mitochondrial PrxIII Antioxidant Defence Pathway: General Properties and Factors Affecting PrxIII Activity and Oligomeric StateJournal of Molecular Biology, 2007
- Inactivation of Thioredoxin Reductases Reveals a Complex Interplay between Thioredoxin and Glutathione Pathways in Arabidopsis DevelopmentPlant Cell, 2007
- Disulfide Bridges in the Mesophilic Triosephosphate Isomerase from Giardia lamblia Are Related to Oligomerization and ActivityJournal of Molecular Biology, 2007
- Cloning, overexpression, purification and preliminary crystallographic studies of a mitochondrial type II peroxiredoxin fromPisum sativumActa Crystallographica Section F Structural Biology and Crystallization Communications, 2006
- Human mitochondrial peroxiredoxin 5 protects from mitochondrial DNA damages induced by hydrogen peroxideFEBS Letters, 2005
- Cloning and characterization of a 2-Cys peroxiredoxin from Pisum sativumJournal of Experimental Botany, 2004
- HIV-1 evades antibody-mediated neutralization through conformational masking of receptor-binding sitesNature, 2002
- Cytochrome c Peroxidase−Cytochrome c Complex: Locating the Second Binding Domain on Cytochrome c Peroxidase with Site-Directed MutagenesisBiochemistry, 2000
- Mouse Peroxiredoxin V Is a Thioredoxin Peroxidase That Inhibits p53-Induced ApoptosisBiochemical and Biophysical Research Communications, 2000