DnaA-stimulated transcriptional activation of orilambda: Escherichia coli RNA polymerase beta subunit as a transcriptional activator contact site.
We present evidence that Escherichia coli RNA polymerase beta subunit may be a transcriptional activator contact site. Stimulation of the activity of the pR promoter by DnaA protein is necessary for replication of plasmids derived from bacteriophage lambda. We found that DnaA activates the pR promoter in vitro. Particular mutations in the rpoB gene were able to suppress negative effects that certain dnaA mutations had on the replication of lambda plasmids; this suppression was allele-specific. When a potential DnaA-binding sequence located several base pairs downstream of the pR promoter was scrambled by in vitro mutagenesis, the pR promoter was no longer activated by DnaA both in vivo and in vitro. Therefore, we conclude that DnaA may contact the beta subunit of RNA polymerase during activation of the pR promoter. A new classification of prokaryotic transcriptional activators is proposed.
Szalewska-Pałasz
A
A
Department of Molecular Biology, Polish Academy of Sciences, Laboratory of Molecular Biology (affiliated with), University of Gdańsk, Kladki 24, 80-822 Gdańsk, Poland.
Wegrzyn
A
A
Błaszczak
A
A
Taylor
K
K
Wegrzyn
G
G
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D010582:Bacteriophage lambda / Q000235:genetics* / Q000502:physiology; D001482:Base Composition; D001665:Binding Sites; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D046911:Macromolecular Substances; D016296:Mutagenesis; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D018741:Replication Origin; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014170:Transformation, Genetic; D014779:Virus Replication; D001616:beta-Galactosidase / Q000378:metabolism
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D012321:DNA-Directed RNA Polymerases; D001616:beta-Galactosidase