7RJ5

The structure of BAM in complex with EspP at 7 Angstrom resolution

Summary for 7RJ5

• Entry DOI: 10.2210/pdb7rj5/pdb
• EMDB information: 24481
• Descriptor: Maltodextrin-binding protein,Autotransporter outer membrane beta-barrel domain-containing protein chimera, Outer membrane protein assembly factor BamA, Outer membrane protein assembly factor BamB, ... (7 entities in total)
• Functional Keywords: bam, espp, hybrid barrel, membrane protein
• Biological source: Escherichia coli; More
• Total number of polymer chains: 6
• Total formula weight: 288080.34

Authors

Wu, R.R.,Noinaj, N. (deposition date: 2021-07-20, release date: 2021-12-22)

Primary citation

Wu, R.,Bakelar, J.W.,Lundquist, K.,Zhang, Z.,Kuo, K.M.,Ryoo, D.,Pang, Y.T.,Sun, C.,White, T.,Klose, T.,Jiang, W.,Gumbart, J.C.,Noinaj, N.
Plasticity within the barrel domain of BamA mediates a hybrid-barrel mechanism by BAM.
Nat Commun, 12:7131-7131, 2021

PubMed Abstract: In Gram-negative bacteria, the biogenesis of β-barrel outer membrane proteins is mediated by the β-barrel assembly machinery (BAM). The mechanism employed by BAM is complex and so far- incompletely understood. Here, we report the structures of BAM in nanodiscs, prepared using polar lipids and native membranes, where we observe an outward-open state. Mutations in the barrel domain of BamA reveal that plasticity in BAM is essential, particularly along the lateral seam of the barrel domain, which is further supported by molecular dynamics simulations that show conformational dynamics in BAM are modulated by the accessory proteins. We also report the structure of BAM in complex with EspP, which reveals an early folding intermediate where EspP threads from the underside of BAM and incorporates into the barrel domain of BamA, supporting a hybrid-barrel budding mechanism in which the substrate is folded into the membrane sequentially rather than as a single unit.

PubMed: 34880256
DOI: 10.1038/s41467-021-27449-4

Experimental method

ELECTRON MICROSCOPY (7 Å)