The transcriptional activator protein FIS: DNA interactions and cooperative interactions with RNA polymerase at the Escherichia coli rrnB P1 promoter.
The E. coli rrnB P1 promoter owes its strength, in part, to the transcriptional activator protein FIS. FIS binds to three sites upstream of the RNA polymerase (RNAP) binding site and increases transcription in vivo four to ten-fold. In this report, hydroxyl radical and DMS footprinting analyses show that FIS binds to its three sites along one side of the DNA helix, and that FIS bound at the promoter-proximal site (site I) and RNAP bound at the promoter are in close proximity. The binding of FIS at site I and RNAP at the promoter are mutually cooperative. These observations support a model for direct interaction between the FIS protein bound at site I and RNAP in transcription activation at rrnB P1. We also find that FIS does not bind cooperatively to its three sites upstream of rrnB P1, and that the relatively small activation associated with FIS bound at sites II and III does not result indirectly by facilitation of binding of FIS to site I.
Department of Bacteriology, University of Wisconsin-Madison 53706.
A J
AJ
Bokal
W
W
Ross
R L
RL
Gourse
D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004275:DNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D003850:Deoxyribonuclease I / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D035021:Factor For Inversion Stimulation Protein; D017665:Hydroxyl Radical; D034982:Integration Host Factors; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D013463:Sulfuric Acid Esters; D014158:Transcription, Genetic; D012407:rRNA Operon
D002352:Carrier Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D035021:Factor For Inversion Stimulation Protein; D034982:Integration Host Factors; D013463:Sulfuric Acid Esters; C440502:integration host factor, E coli; D017665:Hydroxyl Radical; D012321:DNA-Directed RNA Polymerases; D003850:Deoxyribonuclease I; C007482:dimethyl sulfate