title: [Specific association of the CRP-cyclic AMP complex with the control region of the lactose operon of Escherichia coli K 12: a direct fluorimetric study using DNA fragments of different lengths].
abstract: Specific-site binding of the cAMP . CRP complex to the control region of the lactose operon of E. coli was measured directly. All of the protein molecules did bind specifically, and the binding constant for the major CRP site was not dependent on the length (62, 219 or 301 base pairs) of the DNA fragments used. Comparing the values of the binding constant measured for the major site and for the weaker "operator" CRP site, and referring to the published "consensus sequence" derived from the known CRP sites in a series of operons, we suggest that two sub-sites support additive contribution to the total binding free energy.
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D000242:Cyclic AMP / Q000378:metabolism*; D004269:DNA, Bacterial / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D007763:Lac Operon; D011485:Protein Binding; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D000242:Cyclic AMP
vernacular_title: Association spécifique du complexe CRP-AMP-cyclique sur la région de contrôle de l'opéron lactose d'Escherichia coli K 12: une étude fluorimétrique directe utilisant des fragments de DNA de différentes longueurs.