TABLE 1.

Dissociation constants of the interaction of H-ras orientation mutants with the Ras binding domain of C-Raf

In vitro dissociation constants (K_d) of the C-Raf-RBD and mant-GTPγS-bound H-ras (residues 2–189; 100 nm) with or without orientation mutations determined from fluorescence anisotropy measurements. K_d values ± S.E. are listed (n ≥ 4). Statistical analysis did not reveal any significant difference between the three mant-GTPγS-bound H-ras orientation mutants; see under “Experimental Procedures” for details about statistical analysis.

	H-ras, WT	H-ras- R169A/K170A	H-ras- R128A/R135A
Mant-GTPγS Kd (nm)	412 ± 71	327 ± 72	422 ± 76