Figure 5
(a) Ribbon model of crystal structure of CDC42 (Yellow) in complex with PAK6 (Purple) (PDB: 2ODB). P-loop (residues 10-17), Switch I (residues 32–40), and switch II (residues 60–67) of Cdc42 are green, red and cyan, respectively. Nucleotide (cyan), K166 of CDC42 and residues 11-16 of PAK6 are shown in ball-and-stick representation. Hydrogen bond between K166 of CDC42 and PAK6 (carbonyl oxygen of I12) is shown as black dashed line. The second figure shows a model of ubiquitinated (Green) CDC42 (Yellow) in complex with PAK6 (Purple). Finally, a sequence alignment of CRIB domain of PAK2 and PAK6. (b) The same in vitro ubiquitination assay as in Figure 4b was performed and the reaction was then subjected to a PAK-PBD GST pulldown (as described in Materials and Methods) to check for interaction of ubiquitinated Cdc42 and its downstream effector PAK. The ubiquitination of Cdc42 was confirmed in the samples employed for PAK-PBD pulldown (lane 4)
