Crystal structure of the GTPase-activating domain of human p120GAP and implications for the interaction with Ras.Scheffzek, K., Lautwein, A., Kabsch, W., Ahmadian, M.R., Wittinghofer, A.
(1996) Nature 384: 591-596
- PubMed: 8955277
- DOI: 10.1038/384591a0
- PubMed Abstract:
- Molecular Cloning of Two Types of Gap Complementary DNA from Human Placenta
Trahey, M.,Wong, G.,Halenbeck, R.,Rubinfeld, B.,Martin, G.A.,Ladner, M.,Long, C.M.,Crosier, W.J.,Watt, K.,Koths, K.,Mccormick, F.
(1988) Science 242: 1697
- A Cytoplasmic Protein Stimulates Normal N-Ras P21 Gtpase, But Does not Affect Oncogenic Mutants
Trahey, M.,Mccormick, F.
(1987) Science 238: 542
- Crystallization and Preliminary X-Ray Crystallographic Study of the Ras-Gtpase-Activating Domain of Human P120Gap
Scheffzek, K.,Lautwein, A.,Scherer, A.,Franken, S.,Wittinghofer, A.
(1997) Proteins 27: 315
Ras-related GTP-binding proteins function as molecular switches which cycle between GTP-bound 'on'- and GDP-bound 'off'-states. GTP hydrolysis is the common timing mechanism that mediates the return from the 'on' to the 'off'-state. It is usually slo ...
Ras-related GTP-binding proteins function as molecular switches which cycle between GTP-bound 'on'- and GDP-bound 'off'-states. GTP hydrolysis is the common timing mechanism that mediates the return from the 'on' to the 'off'-state. It is usually slow but can be accelerated by orders of magnitude upon interaction with GTPase-activating proteins (GAPs). In the case of Ras, a major regulator of cellular growth, point mutations are found in approximately 30% of human tumours which render the protein unable to hydrolyse GTP, even in the presence of Ras-GAPs. The first structure determination of a GTPase-activating protein reveals the catalytically active fragment of the Ras-specific p120GAP (ref. 2), GAP-334, as an elongated, exclusively helical protein which appears to represent a novel protein fold. The molecule consists of two domains, one of which contains all the residues conserved among different GAPs for Ras. From the location of conserved residues around a shallow groove in the central domain we can identify the site of interaction with Ras x GTP. This leads to a model for the interaction between Ras and GAP that satisfies numerous biochemical and genetic data on this important regulatory process.
Max-Planck-Institut für molekulare Physiologie, Dortmund, Germany.