| Autor: |
Kate S. Carroll, Loubna A. Hammad, Aaron T. Setterdahl, Zhuo Cheng, Carl E. Bauer, Khalilah G. Reddie, Jonathan A. Karty, Jiang Wu |
| Rok vydání: |
2012 |
| Předmět: |
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| Zdroj: |
Molecular Microbiology. 85:734-746 |
| ISSN: |
0950-382X |
| Popis: |
CrtJ from Rhodobacter capsulatus is a regulator of genes involved in the biosynthesis of haem, bacteriochlorophyll, carotenoids as well as structural proteins of the light harvesting-II complex. Fluorescence anisotropy-based DNA-binding analysis demonstrates that oxidized CrtJ exhibits ~20-fold increase in binding affinity over that of reduced CrtJ. Liquid chromatography electrospray tandem ionization mass spectrometric analysis using DAz-2, a sulfenic acid (-SOH)-specific probe, demonstrates that exposure of CrtJ to oxygen or to hydrogen peroxide leads to significant accumulation of a sulfenic acid derivative of Cys420 which is located in the helix-turn-helix (HTH) motif. In vivo labelling with 4-(3-azidopropyl)cyclohexane-1,3-dione (DAz-2) shows that Cys420 also forms a sulfenic acid modification in vivo when cells are exposed to oxygen. Moreover, a Cys420 to Ala mutation leads to a ~60-fold reduction of DNA binding activity while a Cys to Ser substitution at position 420 that mimics a cysteine sulfenic acid results in a ~4-fold increase in DNA binding activity. These results provide the first example where sulfenic acid oxidation of a cysteine in a HTH-motif leads to differential effects on gene expression. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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