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Signal integration in the galactose network of Escherichia coli
- Source :
- Molecular Microbiology. 65:465-476
- Publication Year :
- 2007
- Publisher :
- Wiley, 2007.
-
Abstract
- Summary The gal regulon of Escherichia coli contains genes involved in galactose transport and metabolism. Transcription of the gal regulon genes is regulated in different ways by two iso-regulatory proteins, Gal repressor (GalR) and Gal isorepressor (GalS), which recognize the same binding sites in the absence of d-galactose. DNA binding by both GalR and GalS is inhibited in the presence of d-galactose. Many of the gal regulon genes are activated in the presence of the adenosine cyclic-3′,5′-monophosphate (cAMP)–cAMP receptor protein (CRP) complex. We studied transcriptional regulation of the gal regulon promoters simultaneously in a purified system and attempted to integrate the two small molecule signals, d-galactose and cAMP, that modulate the isoregulators and CRP respectively, at each promoter, using Boolean logic. Results show that similarly organized promoters can have different input functions. We also found that in some cases the activity of the promoter and the cognate gene can be described by different logic gates. We combined the transcriptional network of the galactose regulon, obtained from our experiments, with literature data to construct an integrated map of the galactose network. Structural analysis of the network shows that at the interface of the genetic and metabolic network, feedback loops are by far the most common motif.
- Subjects :
- Cyclic AMP Receptor Protein
Molecular Sequence Data
Repressor
Biology
Regulon
Microbiology
chemistry.chemical_compound
Escherichia coli
Transcriptional regulation
gal operon
Promoter Regions, Genetic
Molecular Biology
Gene
Galactose transport
Base Sequence
Escherichia coli Proteins
Galactose
Biological Transport
Promoter
Gene Expression Regulation, Bacterial
Repressor Proteins
chemistry
Biochemistry
Transcription Factors
Subjects
Details
- ISSN :
- 13652958 and 0950382X
- Volume :
- 65
- Database :
- OpenAIRE
- Journal :
- Molecular Microbiology
- Accession number :
- edsair.doi.dedup.....8ddd0b0adb10994f4d97565984842c02