Figure 6
From: Characterization of the ExoU activation mechanism using EPR and integrative modeling
Activation model of ExoU. ExoU can associate with either the membrane or ubiquitin (purple) individually. Ubiquitin binds the ubiquitin binding domain (blue) but has no major effects in the absence of substrate. ExoU binds the membrane via its membrane localization domain (red)28,29,59 which places the catalytic domain (green, S142 shown as red sphere) near the membrane surface. Loop427–446 (yellow) unfolds and becomes disordered upon membrane association. Upon binding of ExoU to both the membrane and ubiquitin, loop427–446 adopts a new conformation that creates a substrate binding pocket (orange), resulting in hydrolysis and disruption of the membrane.
