The FlhD/FlhC complex, a transcriptional activator of the Escherichia coli flagellar class II operons.
The Escherichia coli flhD operon encodes two genes, flhD and flhC. Both gene products were overproduced and purified. The purified proteins formed a complex consisting of two FlhD and two FlhC molecules. Mobility shift assays showed that the FlhD/FlhC complex had a DNA-binding activity and bound to the upstream regions of fliA, flhB, and fliL operons (class II), which are under direct control of the flhD operon. DNase I footprinting analyses of FlhD/FlhC binding to the three class II promoter regions revealed protection of a 48-bp region of the fliA operon between positions -41 to -88, a 50-bp region of the flhB operon between positions -28 to -77, and a 48-bp region of the fliL operon between positions -29 to -76. In vitro transcription experiments demonstrated that the FlhD/FlhC complex is a transcriptional activator required for the transcription of the three class II operons examined in vitro.
Department of Microbiology and Immunology, University of Illinois at Chicago 60612-7344.
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D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005407:Flagella / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C064971:FliA protein, Bacteria; D011994:Recombinant Proteins; D012808:Sigma Factor; D015534:Trans-Activators; C090552:flhC protein, E coli; C090553:flhD protein, E coli