Analysis of Transmembrane β-Barrel Proteins by Native and Semi-native Polyacrylamide Gel Electrophoresis.

Membrane-embedded β-barrel proteins are important regulators of the outer membrane permeability barrier of Gram-negative bacteria. β-barrels are highly structured domains formed by a series of antiparallel β-strands. Each β-strand is locked in position by hydrogen bonds between its polypeptide backbone and those of the two neighbouring strands in the barrel structure.

Lipoprotein DolP supports proper folding of BamA in the bacterial outer membrane promoting fitness upon envelope stress.

In Proteobacteria, integral outer membrane proteins (OMPs) are crucial for the maintenance of the envelope permeability barrier to some antibiotics and detergents. In Enterobacteria, envelope stress caused by unfolded OMPs activates the sigmaE (σ) transcriptional response. σ upregulates OMP biogenesis factors, including the β-barrel assembly machinery (BAM) that catalyses OMP folding.