Action of prokaryotic enhancer over a distance does not require continued presence of promoter-bound sigma54 subunit.
The mechanism by which an enhancer activates transcription over large distances has been investigated. Activation of the glnAp2 promoter by the NtrC-dependent enhancer in Escherichia coli was analyzed using a purified system supporting multiple-round transcription in vitro. Our results suggest that the enhancer-promoter interaction and the initiation complex must be formed de novo during every round of transcription. No protein remained bound to the promoter after RNA polymerase escaped into elongation. Furthermore, the rate of initiation during the first and subsequent rounds of transcription were very similar, suggesting that there was no functional 'memory' facilitating multiple rounds of transcription. These studies exclude the hypothesis that enhancer action during multiple-round transcription involves the memory of the initial activation event.
Bondarenko
Vladimir
V
Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, 540 East Canfield Avenue, Room 5123, Detroit, MI 48201, USA.
Liu
Ye
Y
Ninfa
Alexander
A
Studitsky
Vasily M
VM
D001426:Bacterial Proteins; D018983:DNA Footprinting; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000378:metabolism*; D003850:Deoxyribonuclease I / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics*; D020035:Holoenzymes / Q000378:metabolism; D046911:Macromolecular Substances; D051922:PII Nitrogen Regulatory Proteins; D011196:Potassium Permanganate / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D021122:Protein Subunits; D051877:RNA Polymerase Sigma 54; D012808:Sigma Factor / Q000378:metabolism*; D013698:Templates, Genetic; D015534:Trans-Activators; D014157:Transcription Factors; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D020035:Holoenzymes; D046911:Macromolecular Substances; D051922:PII Nitrogen Regulatory Proteins; D021122:Protein Subunits; D012808:Sigma Factor; D015534:Trans-Activators; D014157:Transcription Factors; C497876:glnG protein, E coli; C497751:rpoN protein, E coli; D011196:Potassium Permanganate; D012321:DNA-Directed RNA Polymerases; D051877:RNA Polymerase Sigma 54; D003850:Deoxyribonuclease I