8BO2 image
Entry Detail
PDB ID:
8BO2
EMDB ID:
Title:
BAM-EspP complex structure with BamA-S425C/EspP-S1299C mutations in nanodisc
Biological Source:
PDB Version:
Deposition Date:
2022-11-14
Release Date:
2023-04-26
Method Details:
Experimental Method:
Resolution:
3.10 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Outer membrane protein assembly factor BamA
Mutations:S425C
Chain IDs:A
Chain Length:787
Number of Molecules:1
Biological Source:Escherichia coli K-12
Polymer Type:polypeptide(L)
Description:Outer membrane protein assembly factor BamB
Chain IDs:B
Chain Length:392
Number of Molecules:1
Biological Source:Escherichia coli K-12
Polymer Type:polypeptide(L)
Description:Outer membrane protein assembly factor BamC
Chain IDs:C
Chain Length:344
Number of Molecules:1
Biological Source:Escherichia coli K-12
Polymer Type:polypeptide(L)
Description:Outer membrane protein assembly factor BamD
Chain IDs:D
Chain Length:245
Number of Molecules:1
Biological Source:Escherichia coli K-12
Polymer Type:polypeptide(L)
Description:Outer membrane protein assembly factor BamE
Chain IDs:E
Chain Length:123
Number of Molecules:1
Biological Source:Escherichia coli K-12
Polymer Type:polypeptide(L)
Description:Serine protease EspP
Mutations:S1299C
Chain IDs:F (auth: P)
Chain Length:353
Number of Molecules:1
Biological Source:Escherichia coli K-12
Ligand Molecules
Primary Citation
Structural basis of BAM-mediated outer membrane beta-barrel protein assembly.
Nature 617 185 193 (2023)
PMID: 37100902 DOI: 10.1038/s41586-023-05988-8

Abstact

The outer membrane structure is common in Gram-negative bacteria, mitochondria and chloroplasts, and contains outer membrane β-barrel proteins (OMPs) that are essential interchange portals of materials1-3. All known OMPs share the antiparallel β-strand topology4, implicating a common evolutionary origin and conserved folding mechanism. Models have been proposed for bacterial β-barrel assembly machinery (BAM) to initiate OMP folding5,6; however, mechanisms by which BAM proceeds to complete OMP assembly remain unclear. Here we report intermediate structures of BAM assembling an OMP substrate, EspP, demonstrating sequential conformational dynamics of BAM during the late stages of OMP assembly, which is further supported by molecular dynamics simulations. Mutagenic in vitro and in vivo assembly assays reveal functional residues of BamA and EspP for barrel hybridization, closure and release. Our work provides novel insights into the common mechanism of OMP assembly.

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Primary Citation of related structures