Fig. 2: Interactions mediating Rac1 binding to the D site.
From: Structures reveal a key mechanism of WAVE regulatory complex activation by Rac1 GTPase
a Side view of the overall structure of Rac1 (cartoon, gold) binding to the D site (semitransparent surface, green). F37 and Y967 side chains are shown as reference points. b Top view and semitransparent surface charge representation of the D site (calculated using APBS in Pymol45), showing key interactions between Sra1 and Rac1. Yellow dotted lines indicate polar interactions. White dashed line indicates binding surface boundary. For clarity, the backbones of Switch I and II are shown as loops. c, d Structural comparison of Rac1 and the D site in the bound (dark colors) and unbound (light colors, PDB 3SBD for Rac1) states. Curved arrows indicate side chain flipping upon Rac1 binding. Straight arrow indicates translation of polypeptide backbone. Black dashed lines indicate the interdigitated π-π stacking.
