title: The stereochemical course of the ribosome-dependent GTPase reaction of elongation factor G from Escherichia coli.
abstract: The stereochemical course of the ribosome-dependent GTPase reaction of elongation factor G from Escherichia coli has been determined. Guanosine 5'-(gamma-thio)triphosphate stereospecifically labeled with 17O and 18O in the gamma-position was hydrolyzed in the presence of the elongation factor and ribosomes. The configuration of the product, inorganic [16O, 17O, 18O]thiophosphate ws analyzed by 31P NMR after its stereospecific incorporation into adenosine 5'-(beta-thio)triphosphate. The analysis showed that the hydrolysis proceeds with inversion of configuration at the transferred phosphorus atom. It is therefore likely that the hydrolysis occurs in a single step by direct, in-line transfer of the phosphorus from GDP to a water oxygen, without a phosphoenzyme intermediate.
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000032:analysis; D004926:Escherichia coli / Q000201:enzymology*; D020963:GTP Phosphohydrolase-Linked Elongation Factors / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D020653:Peptide Elongation Factor G; D010445:Peptide Elongation Factors / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D012270:Ribosomes / Q000201:enzymology*; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D020653:Peptide Elongation Factor G; D010445:Peptide Elongation Factors; C022571:adenosine 5'-O-(3-thiotriphosphate); D000255:Adenosine Triphosphate; D010744:Phosphoric Monoester Hydrolases; D020963:GTP Phosphohydrolase-Linked Elongation Factors