title: Biochemical and crystallographic characterization of a complex of c-Ha-ras p21 and caged GTP with flash photolysis.
abstract: The GTP binding domain of the c-Ha-ras protooncogene product (p21'c) and the corresponding region from an oncogenic mutant form of the protein in which glycine at position 12 has been replaced by valine [p21'(G12V)] have been crystallized with P3-1-(2-nitro)phenylethylguanosine 5'-O-triphosphate (caged GTP) at their active sites. The crystals give x-ray diffraction patterns to a resolution of better than 0.3 nm. Photolysis can be achieved in the crystal, after which GTP hydrolysis takes place at the rate expected from solution studies. Complete x-ray data sets have been obtained for the starting caged-GTP state and the final GDP state after photolysis and hydrolysis, demonstrating the feasibility of time-resolved structural investigations of the process of GTP hydrolysis.
authors.affiliation: Max-Planck-Institut für Medizinische Forschung, Abteilung Biophysik, Heidelberg, Federal Republic of Germany.
authors.forename: I
authors.initials: I
authors.lastname: Schlichting
authors.forename: G
authors.initials: G
authors.lastname: Rapp
authors.forename: J
authors.initials: J
authors.lastname: John
authors.forename: A
authors.initials: A
authors.lastname: Wittinghofer
authors.forename: E F
authors.initials: EF
authors.lastname: Pai
authors.forename: R S
authors.initials: RS
authors.lastname: Goody
mesh_terms: D001665:Binding Sites; D003460:Crystallization; D006160:Guanosine Triphosphate / Q000378:metabolism / Q000031:analogs & derivatives; D007700:Kinetics; D009154:Mutation; D015689:Oncogene Protein p21(ras) / Q000378:metabolism*; D010782:Photolysis; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000378:metabolism; D013873:Thionucleotides / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D011994:Recombinant Proteins; D013873:Thionucleotides; C061507:P(3)-1-(2-nitro)phenylethylguanosine 5'-O-triphosphate; D006160:Guanosine Triphosphate; D015689:Oncogene Protein p21(ras)