title: Evidence for a nucleotide binding site on the isolated beta subunit from Escherichia coli F1-ATPase. Interaction between nucleotide and aurovertin D binding sites.
abstract: The nucleotide binding capacity and affinity of the isolated beta subunit from Escherichia coli F1-ATPase have been studied with radiolabeled ADP and ATP by an equilibrium dialysis technique. Each mole of beta subunit in the presence of EDTA bound 1 mol of ADP or ATP with Kd values of 25 microM and 50-100 microM, respectively. At a saturating concentration, aurovertin enhanced the affinity of ADP or ATP for the isolated beta subunit by 3-6-fold. The Kd values for the binding of ADP or ATP were also assessed through the enhancing effect of ADP on [14C]aurovertin binding (Issartel, J.-P., Klein, G., Satre, M., & Vignais, P.V. (1983) Biochemistry 22, 3485-3492); the Kd values determined by this approach were several times lower than in the absence of aurovertin, in agreement with results obtained by direct titration with radiolabeled ADP or ATP.
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D001313:Aurovertins / Q000378:metabolism; D001665:Binding Sites; D004926:Escherichia coli / Q000201:enzymology*; D011487:Protein Conformation; D006180:Proton-Translocating ATPases / Q000378:metabolism*
chemical_list: D000227:Adenine Nucleotides; D001313:Aurovertins; D000244:Adenosine Diphosphate; C039026:aurovertin D; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases