title: Stoichiometry of polypeptide chain elongation.
abstract: To quantitate the amount of GTP hydrolyzed during polypeptide chain elongation, an in vitro system containing purified endogenous Escherichia coli polysomes has been developed. The polysomes are washed with 1 M NH4Cl to eliminate endogenous GTPase activities and are depleted of subunits and free ribosomes to diminish the uncoupled elongation factor G-dependent GTP hydrolysis. These polysomes, supplemented with elongation factors, aminoacyl-tRNA, and low concentrations of GTP, incorporate amino acids in their nascent peptide chains. After correcting for a background of uncoupled GTP hydrolysis, it has been found that the incorporation of each molecule of amino acid is associated with the hydrolysis of 2 molecules of GTP.
mesh_terms: D001665:Binding Sites; D004926:Escherichia coli / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D007700:Kinetics; D010441:Peptide Chain Elongation, Translational; D010445:Peptide Elongation Factors; D011132:Polyribosomes / Q000378:metabolism*; D011485:Protein Binding; D046249:Transfer RNA Aminoacylation
chemical_list: D010445:Peptide Elongation Factors; D006160:Guanosine Triphosphate