Interplay between DnaA and SeqA proteins during regulation of bacteriophage lambda pR promoter activity.
DnaA and SeqA proteins are main regulators (positive and negative, respectively) of the chromosome replication in Escherichia coli. Nevertheless, both these replication regulators were found recently to be also transcription factors. Interestingly, both DnaA and SeqA control activity of the bacteriophage lambdap(R) promoter by binding downstream of the transcription start site, which is unusual among prokaryotic systems. Here we asked what are functional relationships between these two transcription regulators at one promoter region. Both in vivo and in vitro studies revealed that DnaA and SeqA can activate the p(R) promoter independently and separately rather than in co-operation, however, increased concentrations of one of these proteins negatively influenced the transcription stimulation mediated by the second regulator. This may suggest a competition between DnaA and SeqA for binding to the p(R) regulatory region. The physiological significance of this DnaA and SeqA-mediated regulation of p(R) is demonstrated by studies on lambda plasmid DNA replication in vivo.
Department of Molecular Biology, University of Gdańsk, Klz.shtsls;adki 24, 80-822, Gdańsk, Poland.
Monika
M
Słomińska
Grazyna
G
Konopa
Sylwia
S
Barańska
Grzegorz
G
Wegrzyn
Alicja
A
Wegrzyn
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000378:metabolism*; D001435:Bacteriophages / Q000502:physiology; D017931:DNA Primers / Q000737:chemistry; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D066298:In Vitro Techniques; D007763:Lac Operon / Q000502:physiology; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication / Q000502:physiology; D001616:beta-Galactosidase / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D017931:DNA Primers; C024013:DNA replication complex protein, Bacteriophage lambda; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; D029968:Escherichia coli Proteins; C089746:SeqA protein, E coli; D014157:Transcription Factors; D014764:Viral Proteins; D001616:beta-Galactosidase