A novel function of the cAMP-CRP complex in Escherichia coli: cAMP-CRP functions as an adaptor for the CytR repressor in the deo operon.
Unlike classical bacterial repressors, the CytR repressor of Escherichia coli cannot independently regulate gene expression. Here we show that CytR binding to the deoP2 promoter relies on interaction with the master gene regulatory protein, CRP, and, furthermore, that cAMP-CRP and CytR bind co-operatively to deoP2. Using mutant promoters we show that tandem, properly spaced DNA-bound cAMP-CRP complexes are required for this co-operative binding. These data suggest that CytR forms a bridge between tandem cAMP-CRP complexes, and that cAMP-CRP functions as an adaptor for CytR. The implications of this new version of negative control in E. coli on bacterial gene expression and on combinatorial gene regulation in higher organisms are discussed.
Søgaard-Andersen
L
L
Department of Molecular Biology, Odense University, Denmark.
Pedersen
H
H
Holst
B
B
Valentin-Hansen
P
P
D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D002872:Chromosome Deletion; D000242:Cyclic AMP / Q000378:metabolism*; D002373:Cyclic AMP Receptor Protein; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D009876:Operon; D011401:Promoter Regions, Genetic; D011953:Receptors, Cyclic AMP / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
D001426:Bacterial Proteins; D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein; C048425:CytR protein, E coli; D029968:Escherichia coli Proteins; D011953:Receptors, Cyclic AMP; D012097:Repressor Proteins; D000242:Cyclic AMP