| Title | Regulation of the sufABCDSE Operon by Fur |
|---|---|
| Author | Joon-Hee Lee, Won-Sik Yeo, and Jung-Hye Roe * |
| Address | Laboratory of Molecular Microbiology, School of Biological Sciences,and Institute of Microbiology, Seoul National University, Seoul 151-742, Korea (Received March 14, 2003 / Accepted May 21, 2003) |
| Bibliography | Journal of Microbiology, 41(2),109-114, 2003, |
| DOI | |
| Key Words | Fur, superoxide, iron, SoxRS, oxidant induction, RpoS |
| Abstract | A promoter that is inducible by paraquat and menadione, the superoxide generators, independently of soxRS has been found in front of the sufABCDSE operon in Escherichia coli. Based on the observation that SufA is a holomog of IscA that functions in the assembly of iron sulfur cluster and the sufA promoter (sufAp) contains a putative Fur-binding consensus, we investigated whether this gene is regulated by Fur, a ferric uptake regulator. When examined in several sufAp-lacZ chromosomal fusion strains, sufAp was induced by EDTA, an iron chelator and a well-known Fur-inducer. The basal level of sufA expression increased dramatically in fur mutant, suggesting repression of sufAp by Fur. The derepression in fur mutant and EDTA-induction of sufA expression required nucleotides up to -61, where a putative Fur box is located. Purified Fur protein bound to the DNA fragment containing the putative Fur box between -35 and -10 promoter elements. The regulation by Fur and menadione induction of sufAp acted independently. The rpoS mutation increased sufA induction by menadione, suggesting that the stationary sigma factor RpoS acts negatively on sufA induction. |
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