Distortion of the bilayer and dynamics of the BAM complex in lipid nanodiscs.

ABSTRACT: The β-barrel assembly machinery (BAM) catalyses the folding and insertion of β-barrel outer membrane proteins (OMPs) into the outer membranes of Gram-negative bacteria by mechanisms that remain unclear. Here, we present an ensemble of cryoEM structures of the E. coli BamABCDE (BAM) complex in lipid nanodiscs, determined using multi-body refinement techniques. These structures, supported by single-molecule FRET measurements, describe a range of motions in the BAM complex, mostly localised within the periplasmic region of the major subunit BamA. The β-barrel domain of BamA is in a 'lateral open' conformation in all of the determined structures, suggesting that this is the most energetically favourable species in this bilayer. Strikingly, the BAM-containing lipid nanodisc is deformed, especia

SUBMITTER: Iadanza MG 

PROVIDER: S-EPMC7736308 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature