Autor: |
Doni D; Department of Biology, University of Padova, 35121 Padova, Italy., Cavallari E; Department of Biology, University of Padova, 35121 Padova, Italy.; Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France., Noguera ME; Department of Physiology and Molecular and Cellular Biology, Institute of Biosciences, Biotechnology and Translational Biology (iB3), Faculty of Exact and Natural Sciences, University of Buenos Aires, Intendente Güiraldes 2160, Buenos Aires C1428EG, Argentina.; Institute of Biological Chemistry and Physical Chemistry, Dr Alejandro Paladini (UBA-CONICET), University of Buenos Aires, Junín 956, Buenos Aires 1113AAD, Argentina.; Department of Science and Technology, National University of Quilmes, Roque Saenz Peña 352, Bernal B1876BXD, Argentina., Gentili HG; Department of Physiology and Molecular and Cellular Biology, Institute of Biosciences, Biotechnology and Translational Biology (iB3), Faculty of Exact and Natural Sciences, University of Buenos Aires, Intendente Güiraldes 2160, Buenos Aires C1428EG, Argentina., Cavion F; Department of Biology, University of Padova, 35121 Padova, Italy., Parisi G; Department of Science and Technology, National University of Quilmes, Roque Saenz Peña 352, Bernal B1876BXD, Argentina., Fornasari MS; Department of Science and Technology, National University of Quilmes, Roque Saenz Peña 352, Bernal B1876BXD, Argentina., Sartori G; Department of Biomedical Sciences, University of Padova, 35121 Padova, Italy., Santos J; Department of Physiology and Molecular and Cellular Biology, Institute of Biosciences, Biotechnology and Translational Biology (iB3), Faculty of Exact and Natural Sciences, University of Buenos Aires, Intendente Güiraldes 2160, Buenos Aires C1428EG, Argentina., Bellanda M; Department of Chemical Sciences, University of Padova, 35131 Padova, Italy.; Consiglio Nazionale delle Ricerche Institute of Biomolecular Chemistry, 35131 Padova, Italy., Carbonera D; Department of Chemical Sciences, University of Padova, 35131 Padova, Italy., Costantini P; Department of Biology, University of Padova, 35121 Padova, Italy., Bortolus M; Department of Chemical Sciences, University of Padova, 35131 Padova, Italy. |
Abstrakt: |
Nqo15 is a subunit of respiratory complex I of the bacterium Thermus thermophilus , with strong structural similarity to human frataxin (FXN), a protein involved in the mitochondrial disease Friedreich's ataxia (FRDA). Recently, we showed that the expression of recombinant Nqo15 can ameliorate the respiratory phenotype of FRDA patients' cells, and this prompted us to further characterize both the Nqo15 solution's behavior and its potential functional overlap with FXN, using a combination of in silico and in vitro techniques. We studied the analogy of Nqo15 and FXN by performing extensive database searches based on sequence and structure. Nqo15's folding and flexibility were investigated by combining nuclear magnetic resonance (NMR), circular dichroism, and coarse-grained molecular dynamics simulations. Nqo15's iron-binding properties were studied using NMR, fluorescence, and specific assays and its desulfurase activation by biochemical assays. We found that the recombinant Nqo15 isolated from complex I is monomeric, stable, folded in solution, and highly dynamic. Nqo15 does not share the iron-binding properties of FXN or its desulfurase activation function. |