In vitro transcriptional analysis of TyrR-mediated activation of the mtr and tyrP+3 promoters of Escherichia coli.
In order to understand the mechanism by which the TyrR protein activates transcription from the mtr and tyrP+3 promoters, we have carried out in vitro transcription experiments with supercoiled DNA templates. We have shown that addition of the histone-like protein HU or integration host factor (IHF) greatly inhibited the transcription from the mtr and tyrP+3 promoters. In the presence of phenylalanine, the wild-type TyrR protein, but not a mutant TyrR protein (activation negative), was able to relieve the HU- or IHF-mediated inhibition of transcription. In contrast, the alleviation of the HU- or IHF-mediated transcription inhibition by the wild-type TyrR protein did not occur when a mutant RNA polymerase with a C-terminally truncated alpha subunit was used to carry out the transcription reaction.
Yang
J
J
Department of Microbiology, The University of Melbourne, Parkville, Victoria, Australia.
Camakaris
H
H
Pittard
A J
AJ
D026905:Amino Acid Transport Systems; D026921:Amino Acid Transport Systems, Neutral; D001426:Bacterial Proteins / Q000235:genetics* / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics*; D004278:DNA, Superhelical; D004268:DNA-Binding Proteins / Q000494:pharmacology; D003850:Deoxyribonuclease I / Q000378:metabolism; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D034982:Integration Host Factors; D026901:Membrane Transport Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000494:pharmacology*; D014157:Transcription Factors / Q000494:pharmacology*; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000187:drug effects*
D026905:Amino Acid Transport Systems; D026921:Amino Acid Transport Systems, Neutral; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004278:DNA, Superhelical; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D034982:Integration Host Factors; D026901:Membrane Transport Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C069256:TyrR protein, E coli; C040330:histone-like protein HU, bacteria; C069255:mtr protein, E coli; C057333:tyrP protein, E coli; D003850:Deoxyribonuclease I