A functional assay in Escherichia coli to detect non-assisted interaction between galactose repressor dimers.
Among the Escherichia coli operons repressed from multiple sites on DNA, the galactose operon is unique: its repression requires an auxiliary protein, HU, to assist cooperative repressor binding to two distant DNA sites. Here we show that GalR can still mediate repression from distant sites in an artificial and simplified regulatory region which totally disturbs the organisation of the natural interactions. This simple and unexpected cooperation of a protein incapable of self-association in solution might be involved in regulation of the gal operon. Furthermore, the assay may be generalised to detection of rather weak cooperative interactions between DNA-bound proteins.
Perez
N
N
Equipe 'Interactions à Distance', CNRS UMR 8532, Institut Gustave Roussy (PR2), 39 Rue Camille Desmoulins, 94 805 Villejuif Cedex, France.
Rehault
M
M
Amouyal
M
M
D001426:Bacterial Proteins / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D009690:Nucleic Acid Conformation; D009875:Operator Regions, Genetic; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C050993:Galactose repressor proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C040330:histone-like protein HU, bacteria