Cysteine Mutational Studies Provide Insight into a Thiol-Based Redox Switch Mechanism of Metal and DNA Binding in FurA fromAnabaenasp. PCC 7120
| Autor: | Lellys M. Contreras, Adrián Velázquez-Campoy, José L. Neira, Silvia Pellicer, María Luisa Peleato, Laura Botello-Morte, Violeta C. Sein-Echaluce, Olga Abian, María F. Fillat, María Teresa Bes |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
chemistry.chemical_classification Physiology Clinical Biochemistry Isothermal titration calorimetry Cell Biology Biology Biochemistry Redox Serine Original Research Communications 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology chemistry Thiol General Earth and Planetary Sciences Molecular Biology Gene Corepressor DNA General Environmental Science Cysteine |
| Zdroj: | Antioxidants & Redox Signaling. 24:173-185 |
| ISSN: | 1557-7716 1523-0864 |
| Popis: | Aims: The ferric uptake regulator (Fur) is the main transcriptional regulator of genes involved in iron homeostasis in most prokaryotes. FurA from Anabaena sp. PCC 7120 contains five cysteine residues, four of them arranged in two redox-active CXXC motifs. The protein needs not only metal but also reducing conditions to remain fully active in vitro. Through a mutational study of the cysteine residues present in FurA, we have investigated their involvement in metal and DNA binding. Results: Residue C101 that belongs to a conserved CXXC motif plays an essential role in both metal and DNA binding activities in vitro. Substitution of C101 by serine impairs DNA and metal binding abilities of FurA. Isothermal titration calorimetry measurements show that the redox state of C101 is responsible for the protein ability to coordinate the metal corepressor. Moreover, the redox state of C101 varies with the presence or absence of C104 or C133, suggesting that the environments of these cysteines are mutually interdependent. Innovation: We propose that C101 is part of a thiol/disulfide redox switch that determines FurA ability to bind the metal corepressor. Conclusion: This mechanism supports a novel feature of a Fur protein that emerges as a regulator, which connects the response to changes in the intracellular redox state and iron management in cyanobacteria. Antioxid. Redox Signal. 24, 173–185. |
| Databáze: | OpenAIRE |
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