Restored DNA-binding of the cAMP-CRP activator complex reestablishes negative regulation by the CytR repressor in the deoP2 promoter in Escherichia coli.
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.
Søgaard-Andersen
L
L
Department of Molecular Biology, Odense University, Denmark.
Valentin-Hansen
P
P
D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D002373:Cyclic AMP Receptor Protein; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000502:physiology*; D011953:Receptors, Cyclic AMP / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012097:Repressor Proteins / Q000378:metabolism / Q000502:physiology*; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein; C048425:CytR protein, E coli; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D011953:Receptors, Cyclic AMP; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D000242:Cyclic AMP; D015719:Single-Strand Specific DNA and RNA Endonucleases; D001616:beta-Galactosidase