8.A.99. The BLP Braun's Lipoprotein (Lpp) Family
Gram-negative bacteria such as Escherichia coli are protected by a complex cell envelope with covalent and noncovalent protein interactions linking the outer membrane to the aqueous periplasmic region. Samsudin et al. 2017 showed that Braun's lipoprotein tilts and bends, and thereby lifts the cell wall closer to the outer membrane. Both monomers and dimers of the outer membrane porin OmpA can interact with peptidoglycan in the presence of Braun's lipoprotein, but in the absence of the latter, only dimers of OmpA show a propensity to form contacts with peptidoglycan. This provides one mechanism by which the cell wall attaches to the outer membrane (Samsudin et al. 2017).