title: The binding of nucleotides and metal ions to elongation factor Tu from Bacillus stearothermophilus as studied by equilibrium dialysis.
abstract: EF-Tu from B. stearothermophilus binds divalent metal ions even in the absence of guanine nucleotides. The association constants necessary for characterizing the multiple equilibria between EF-Tu, GDP and the divalent ions magnesium and manganese were determined by equilibrium dialysis. The constants are 4.6 X 10(4) M-1 and 5.4 X 10(5) M-1 for the binding of Mg2 and 1.0 X 10(5) M-1 and 1.1 X 10(6) M-1 for the binding of Mn2 to EF-Tu and EF-Tu . GDP, respectively. In the absence of divalent ions EF-Tu binds GMP, GDP and GTP with association constants of 3 x 10(3) M-1, 1.7 x 10(7) M-1 and 1.3 x 10(6) M-1, respectively. The binding of GDP in the presence of metal ions is an order of magnitude stronger than in the absence of metal ions.
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D003956:Dialysis; D001411:Geobacillus stearothermophilus / Q000378:metabolism*; D006150:Guanine Nucleotides / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism*; D006157:Guanosine Monophosphate / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism*; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism*; D008345:Manganese / Q000378:metabolism*; D010444:Peptide Elongation Factor Tu; D010445:Peptide Elongation Factors / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D001426:Bacterial Proteins; D006150:Guanine Nucleotides; D010445:Peptide Elongation Factors; D006153:Guanosine Diphosphate; D008345:Manganese; D006157:Guanosine Monophosphate; D006160:Guanosine Triphosphate; D010444:Peptide Elongation Factor Tu; D008274:Magnesium