Restored DNA-binding of the CAMP-CRP activator complex reestablishes negative regulation by the CytR repressor in the deoP2 promoter in Escherichia coli
✍ Scribed by Søgaard-Andersen, Lotte ;Valentin-Hansen, Poul
- Publisher
- Springer
- Year
- 1991
- Tongue
- English
- Weight
- 717 KB
- Volume
- 231
- Category
- Article
- ISSN
- 0026-8925
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✦ Synopsis
We have investigated in vivo the coupling between CytR regulation of the deoP2 promoter in Escherichia coli and the DNA-binding specificity of the cAMP-CRP (cAMP receptor protein) complex in order to obtain a more detailed picture of the role played by cAMP-CRP in CytR regulation. By introducing CRP proteins that exhibit an altered DNA binding specificity into a strain containing a mutant deoP2 promoter in which cAMP-CRP activation was decreased and CytR regulation completely abolished, we show that CytR regulation of this promoter can be reestablished by restored the DNA binding of the cAMP-CRP complex. Hence, CytR regulation of deoP2 can be modulated by simply varying DNA binding of cAMP-CRP. These data confirm the crucial role played by the cAMP-CRP activator complex in CytR regulation of the deoP2 promoter.