Inducer-Modulated Cooperative Binding of the Tetrameric CggR Repressor to Operator DNA
| Autor: | Álvaro Ortega, Thierry Doan, Stéphane Aymerich, Nathalie Declerck, Silvia Zorrilla, Germán Rivas, Emmanuel Margeat, Carlos Alfonso, Catherine A. Royer |
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| Přispěvatelé: | Centre de Biochimie Structurale [Montpellier] (CBS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM), Microbiologie et Génétique Moléculaire (MGM), Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Departamento de Química Física, Facultad de Química, Universidad de Murcia, Marie Curie intra-European fellowship, grant No. BFU2005-04087-C02-01 pour German Rivas, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC) |
| Rok vydání: | 2007 |
| Předmět: |
DNA
Bacterial Operator Regions (Genetics) Operator Regions Genetic Operon Biophysics Repressor Cooperativity Biology 03 medical and health sciences chemistry.chemical_compound Fructosediphosphates Direct repeat MESH: Protein Binding Inducer MESH: Fructosediphosphates Binding site 030304 developmental biology 0303 health sciences Binding Sites MESH: Kinetics 030306 microbiology Bacterial MESH: Operator Regions (Genetics) Proteins Cooperative binding [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry Molecular Biology/Molecular biology DNA MESH: DNA Bacterial Repressor Proteins Kinetics Biochemistry chemistry MESH: Binding Sites MESH: Repressor Proteins Protein Binding |
| Zdroj: | Biophysical Journal Biophysical Journal, Biophysical Society, 2007, 92 (9), pp.3215-27. ⟨10.1529/biophysj.106.095109⟩ |
| ISSN: | 0006-3495 1542-0086 |
| DOI: | 10.1529/biophysj.106.095109 |
| Popis: | The central glycolytic genes repressor (CggR) controls the transcription of the gapA operon encoding five key glycolytic enzymes in Bacillus subtilis. CggR recognizes a unique DNA target sequence comprising two direct repeats and fructose-1,6-bisphosphate (FBP) is the inducer that negatively controls this interaction. We present here analytical ultracentrifugation and fluorescence anisotropy experiments that demonstrate that CggR binds as a tetramer to the full-length operator DNA in a highly cooperative manner. We also show that CggR binds as a dimer to each direct repeat, the affinity being approximately 100-fold higher for the 3' repeat. In addition, our studies reveal a bimodal effect of FBP on the repressor/operator interaction. At micromolar concentrations, FBP leads to a change in the conformational dynamics of the complex. In the millimolar range, without altering the stoichiometry, FBP leads to a drastic reduction in the affinity and cooperativity of the complex. This bimodal response suggests the existence of two sugar-binding sites in the repressor, a high affinity site at which FBP acts as a structural co-factor and a low affinity site underlying the molecular mechanism of gapA induction. |
| Databáze: | OpenAIRE |
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