title: Multiple allosteric effectors control the affinity of DasR for its target sites.
abstract: The global transcriptional regulator DasR connects N-acetylglucosamine (GlcNAc) utilization to the onset of morphological and chemical differentiation in the model actinomycete Streptomyces coelicolor. Previous work revealed that glucosamine-6-phosphate (GlcN-6P) acts as an allosteric effector which disables binding by DasR to its operator sites (called dre, for DasR responsive element) and allows derepression of DasR-controlled/GlcNAc-dependent genes. To unveil the mechanism by which DasR controls S. coelicolor development, we performed a series of electromobility shift assays with histidine-tagged DasR protein, which suggested that N-acetylglucosamine-6-phosphate (GlcNAc-6P) could also inhibit the formation of DasR-dre complexes and perhaps even more efficiently than GlcN-6P. The possibility that GlcNAc-6P is indeed an efficient allosteric effector of DasR was further confirmed by the high and constitutive activity of the DasR-repressed nagKA promoter in the nagA mutant, which lacks GlcNAc-6P deaminase activity and therefore accumulates GlcNAc-6P. In addition, we also observed that high concentrations of organic or inorganic phosphate enhanced binding of DasR to its recognition site, suggesting that the metabolic status of the cell could determine the selectivity of DasR in vivo, and hence its effect on the expression of its regulon.
authors.affiliation: Center for Protein Engineering, Institut de chimie B6a, University of Liège, B-4000 Liège, Belgium.
authors.forename: Elodie
authors.initials: E
authors.lastname: Tenconi
authors.affiliation: Molecular Biotechnology, Institute of Biology Leiden, Leiden University, Sylviusweg 72, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
authors.forename: Mia
authors.initials: M
authors.lastname: Urem
authors.affiliation: Molecular Biotechnology, Institute of Biology Leiden, Leiden University, Sylviusweg 72, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
authors.forename: Magdalena A
authors.initials: MA
authors.lastname: Świątek-Połatyńska
authors.affiliation: Department of Oecotrophologie, Münster University of Applied Sciences, Corrensstr. 25, 48149 Münster, Germany.
authors.forename: Fritz
authors.initials: F
authors.lastname: Titgemeyer
authors.affiliation: Lehrstuhl für Biotechnik, Department of Biology, Friedrich-Alexander University Erlangen-Nuremberg, Henkestrasse 91, D-91052 Erlangen, Germany.
authors.forename: Yves A
authors.initials: YA
authors.lastname: Muller
authors.affiliation: Molecular Biotechnology, Institute of Biology Leiden, Leiden University, Sylviusweg 72, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
authors.forename: Gilles P
authors.initials: GP
authors.lastname: van Wezel
authors.affiliation: Center for Protein Engineering, Institut de chimie B6a, University of Liège, B-4000 Liège, Belgium. Electronic address: srigali@ulg.ac.be.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Rigali
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D000494:Allosteric Regulation; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D018085:Regulon; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D048372:Streptomyces coelicolor / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; C010004:N-acetylglucosamine 6-phosphate; D000117:Acetylglucosamine
keywords: Allosteric effector; DNA-protein interaction; Gene expression regulation; Ligand; Nacetylglucosamine