|
Figure 6.
Figure 6. Effector-Facilitated Conformational Changes in
Rac/Cdc42 Proteins
Comparison of switch I regions of
uncomplexed, GTP analog-bound Ras (pdb: 121P) (A) with an
overlay of Rac2 and Cdc42 uncomplexed, GTP analog-bound
structures (pdb: 2w2v and 2QRZ) ([B], left) and Rac2 and Cdc42
GTP analog-bound structures (overlay) from complexes with
PLCγ[2] (pdb: 2w2x) and Par6 (pdb: 1NF3), respectively ([B],
right). Conformations of switch I region and orientation of
indicated key residues in free Rac/CDC42-(GTP) proteins and in
complexes with their effectors are clearly different. Binding of
several effectors to Rac/Cdc42 proteins involves interaction
with switch I residues Val36 and Phe37 that stabilizes
signaling-active (state 2) conformation where other switch I
residues, Thr35 and Tyr32, can coordinate γ-phosphate of GTP.
|
