title: The mechanism of guanosine nucleotide hydrolysis by p21 c-Ha-ras. The stereochemical course of the GTPase reaction.
abstract: The use of guanosine 5'-O-(gamma-thio)triphosphate as a substrate for p21 c-Ha-ras was established. By using chirally labeled [gamma-17O,18O]guanosine 5'-O-(gamma-thio)triphosphate, the stereochemical course of the GTPase reaction was determined. The analysis shows that the hydrolysis occurs with inversion at the gamma-phosphorus. This shows that the most likely mechanism is a single step, in-line transfer, without a phosphoenzyme or other phosphorylated intermediate.
authors.affiliation: Max-Planck Institut für Medizinische Forschung, Abteilung Biophysik, Heidelberg, West Germany.
authors.forename: J
authors.initials: J
authors.lastname: Feuerstein
authors.forename: R S
authors.initials: RS
authors.lastname: Goody
authors.forename: M R
authors.initials: MR
authors.lastname: Webb
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism*; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras); D011994:Recombinant Proteins / Q000378:metabolism; D013237:Stereoisomerism; D013873:Thionucleotides / Q000378:metabolism
chemical_list: D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D013873:Thionucleotides; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D010744:Phosphoric Monoester Hydrolases; D020558:GTP Phosphohydrolases; D016283:Proto-Oncogene Proteins p21(ras)