Three-dimensional structures and properties of a transforming and a nontransforming glycine-12 mutant of p21H-ras.Franken, S.M., Scheidig, A.J., Krengel, U., Rensland, H., Lautwein, A., Geyer, M., Scheffzek, K., Goody, R.S., Kalbitzer, H.R., Pai, E.F., Wittinghofer, A.
(1993) Biochemistry 32: 8411-8420
- PubMed: 8357792
- Primary Citation of Related Structures:  821P
- PubMed Abstract:
- Three-Dimensional Structures of H-Ras P21 Mutants: Molecular Basis for Their Inability to Function as Signal Switch Molecules
Krengel, U.,Schlichting, I.,Scherer, A.,Schumann, R.,Frech, M.,John, J.,Kabsch, W.,Pai, E.F.,Wittinghofer, A.
(1990) Cell 62: 539
- Refined Crystal Structure of the Triphosphate Conformation of H-Ras P21 at 1.35 Angstroms Resolution: Implications for the Mechanism of GTP Hydrolysis
Pai, E.F.,Krengel, U.,Petsko, G.A.,Goody, R.S.,Kabsch, W.,Wittinghofer, A.
(1990) Embo J. 9: 2351
The three-dimensional structures and biochemical properties of two mutants of the G-domain (residues 1-166) of p21H-ras, p21 (G12D) and p21 (G12P), have been determined in the triphosphate-bound form using guanosine 5'-(beta,gamma-imido)triphosphate ...
The three-dimensional structures and biochemical properties of two mutants of the G-domain (residues 1-166) of p21H-ras, p21 (G12D) and p21 (G12P), have been determined in the triphosphate-bound form using guanosine 5'-(beta,gamma-imido)triphosphate (GppNHp). They correspond to the most frequent oncogenic and the only nononcogenic mutation of Gly-12, respectively. The G12D mutation is the only mutant analyzed so far that crystallizes in a space group different from wild type, and the atomic model of the protein shows the most drastic changes of structure around the active site as compared to wild-type p21. This is due to the interactions of the aspartic acid side chain with Tyr-32, Gln-61, and the gamma-phosphate, which result in reduced mobility of these structural elements. The interaction between the carboxylate group of Asp-12 and the gamma-phosphate is mediated by a shared proton, which we show by 31P NMR measurements to exist in solution as well. The structure of p21 (G12P) is remarkably similar to that of wild-type p21 in the active site, including the position of the nucleophilic water. The pyrrolidine ring of Pro-12 points outward and seems to be responsible for the weaker affinity toward GAP (GTPase-activating protein) and the failure of GAP to stimulate GTP hydrolysis.
Abteilung Biophysik, Max-Planck-Institut für Medizinische Forschung, Heidelberg, Germany.