Distribution of (A) RMSDs of the Cα atom, (B) number of interresidue NOEs per residue, and (C) order parameter (17) for Cdc42Hs-GDP and Cdc42Hs(F28L)-GDP. The wildtype data for (A) and (B) were taken from Feltham et al. (9) and are shown in black (the Cdc42(F28L) data is shown in red). The data for (C) was from Adams et al. (17) and the wildtype data is shown with open squares and the Cdc42Hs(F28L) data is shown with closed squares. The gray boxes indicate the positions of the nucleotide binding pocket, and the blue boxes indicate the positions of Switch I, Switch II, and the insert region. The Switch I and II regions are poorly defined and the RMSD values have been removed. The difference between the insert region of wildtype and F28L arises largely due to the unavailability of the 13C-separated NOESY experiment for F28L (see Methods). Although still poorly defined relative to the core of the protein, the structure is somewhat more constrained in wildtype due to several long-range sidechain-sidechain NOEs.