Fig. 6.

Model for aPBP activation by lipoprotein partners. Shown are schematics representing the structures of PBP1a and PBP1b in the cell envelope bound to their cognate lipoprotein partner. Genetic results suggest that both LpoA and LpoB activate their target synthase by directly or indirectly inducing changes in the interdomain linker region (lavender, linker domain, LD) which are then communicated to the enzymatic domains. Thus, even though the two aPBPs have different accessory domains and bind different partners, they may be activated by a similar mechanism.