1. Boriack-Sjodin, P. A., Margarit, S. M., Bar-Sagi, D. & Kuriyan, J. Nature 394, 337–343 (1998).
2. Bourne, H., Sanders, D. & McCormick, F. Nature 348, 125–132 (1990).
3. Scheffzek, K. et al. Science 277, 333–338 (1997).
4. Feig, L. Curr. Opin. Cell Biol. 6, 204–211 (1994).
5. Lenzen, C., Cool, R., Prinz, H., Kuhlmann, J. & Wittinghofer, A. Biochemistry 37, 7420–7430 (1998).