Transcription regulation by tandem-bound FNR at Escherichia coli promoters.
FNR is an Escherichia coli transcription factor that regulates the transcription of many genes in response to anaerobiosis. We have constructed a series of artificial FNR-dependent promoters, based on the melR promoter, in which a consensus FNR binding site was centered at position -41.5 relative to the transcription start site. A second consensus FNR binding site was introduced at different upstream locations, and promoter activity was assayed in vivo. FNR can activate transcription from these promoters when the upstream FNR binding site is located at many different positions. However, sharp repression is observed when the upstream-bound FNR is located near positions -85 or -95. This repression is relieved by the FNR G74C substitution mutant, previously identified as being defective in transcription repression at the yfiD promoter. A parallel series of artificial FNR-dependent promoters, carrying a consensus FNR binding site at position -61.5 and a second upstream DNA site for FNR, was also constructed. Again, promoter activity was repressed by FNR when the upstream-bound FNR was located at particular positions.
Barnard
Anne M L
AM
School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
Green
Jeffrey
J
Busby
Stephen J W
SJ
D001483:Base Sequence; D001665:Binding Sites; D018983:DNA Footprinting; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014158:Transcription, Genetic
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C060704:FNR protein, E coli; D007506:Iron-Sulfur Proteins