Figure 2. EspFU mimics the N-WASP autoinhibitory C helix.
a, Structure of autoinhibited fragment of WASP7, highlighting the C helix (green) and three critical side chains (red). b, EspFU can competitively disrupt the N-WASP autoinhibitory interaction (in trans) in a GST-pulldown assay. c, Alanine scanning mutagenesis shows similar pattern of critical residues in N-WASP C helix and EspFU (repeat 4, residues 1–17) (assayed by binding to GBD in a GST-pulldown assay). d, Model comparing N-WASP activation by Cdc42 and EspFU. e, PAK kinase assay showing phosphorylation of myelin basic protein (MBP). PAK2 alone is autoinhibited – Cdc42 activates it, but EspFU does not.
