4HDJ

Crystal Structure of BamB from Pseudomonas aeruginosa


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.160 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Crystal structure of BamB from Pseudomonas aeruginosa and functional evaluation of its conserved structural features.

Jansen, K.B.Baker, S.L.Sousa, M.C.

(2012) Plos One 7: e49749-e49749

  • DOI: 10.1371/journal.pone.0049749

  • PubMed Abstract: 
  • The assembly of β-barrel Outer Membrane Proteins (OMPs) in the outer membrane is essential for gram-negative bacteria. The process requires the β-Barrel Assembly Machine (BAM), a multiprotein complex that, in E. coli, is composed of the OMP BamA and ...

    The assembly of β-barrel Outer Membrane Proteins (OMPs) in the outer membrane is essential for gram-negative bacteria. The process requires the β-Barrel Assembly Machine (BAM), a multiprotein complex that, in E. coli, is composed of the OMP BamA and four lipoproteins BamB-E. Whereas BamA and BamD are essential, deletion of BamB, C or E produce membrane permeability defects. Here we present the high-resolution structure of BamB from Pseudomonas aeruginosa. This protein can complement the deletion of bamB in E. coli indicating that they are functionally equivalent. Conserved structural features include an eight-bladed β-propeller fold stabilized by tryptophan docking motifs with a central pore about 8 Å in diameter at the narrowest point. This pore distinguishes BamB from related β-propellers, such as quinoprotein dehydrogenases. However, a double mutation designed to block this pore was fully functional indicating that the opening is not essential. Two loops protruding from the bottom of the propeller are conserved and mediate binding to BamA. Conversely, an additional loop only present in E. coli BamB is not required for function. A cluster of highly conserved residues in a groove between blades 6 and 7 is crucial for proper BamB folding or biogenesis. It has been proposed that BamB may bind nascent OMPs by β-augmentation to its propeller outer strands, or recognize the aromatic residue signature at the C-terminus of OMPs. However, Isothermal Titration Calorimetry experiments and structural analysis do not support these proposals. The structural and mutagenesis analysis suggests that the main function of BamB is to bind and modulate BamA, rather than directly interact with nascent OMPs.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado, United States of America.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Outer membrane protein assembly factor BamB
A
367Pseudomonas aeruginosa (strain ATCC 15692 / PAO1 / 1C / PRS 101 / LMG 12228)Gene Names: bamB
Find proteins for Q9HXJ7 (Pseudomonas aeruginosa (strain ATCC 15692 / PAO1 / 1C / PRS 101 / LMG 12228))
Go to UniProtKB:  Q9HXJ7
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.160 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 82.984α = 90.00
b = 82.984β = 90.00
c = 83.380γ = 120.00
Software Package:
Software NamePurpose
PHENIXrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-04-24
    Type: Initial release