4PK1

Structure of BamB fused to a BamA POTRA domain fragment


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.1 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.251 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal Structure of BamB Bound to a Periplasmic Domain Fragment of BamA, the Central Component of the beta-Barrel Assembly Machine.

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

(2015) J.Biol.Chem. 290: 2126-2136

  • DOI: 10.1074/jbc.M114.584524

  • PubMed Abstract: 
  • The β-barrel assembly machinery (BAM) mediates folding and insertion of β-barrel outer membrane proteins (OMPs) into the outer membrane of Gram-negative bacteria. BAM is a five-protein complex consisting of the β-barrel OMP BamA and lipoproteins BamB ...

    The β-barrel assembly machinery (BAM) mediates folding and insertion of β-barrel outer membrane proteins (OMPs) into the outer membrane of Gram-negative bacteria. BAM is a five-protein complex consisting of the β-barrel OMP BamA and lipoproteins BamB, -C, -D, and -E. High resolution structures of all the individual BAM subunits and a BamD-BamC complex have been determined. However, the overall complex architecture remains elusive. BamA is the central component of BAM and consists of a membrane-embedded β-barrel and a periplasmic domain with five polypeptide translocation-associated (POTRA) motifs thought to interact with the accessory lipoproteins. Here we report the crystal structure of a fusion between BamB and a POTRA3-5 fragment of BamA. Extended loops 13 and 17 protruding from one end of the BamB β-propeller contact the face of the POTRA3 β-sheet in BamA. The interface is stabilized by several hydrophobic contacts, a network of hydrogen bonds, and a cation-π interaction between BamA Tyr-255 and BamB Arg-195. Disruption of BamA-BamB binding by BamA Y255A and probing of the interface by disulfide bond cross-linking validate the physiological relevance of the observed interface. Furthermore, the structure is consistent with previously published mutagenesis studies. The periplasmic five-POTRA domain of BamA is flexible in solution due to hinge motions in the POTRA2-3 linker. Modeling BamB in complex with full-length BamA shows BamB binding at the POTRA2-3 hinge, suggesting a role in modulation of BamA flexibility and the conformational changes associated with OMP folding and insertion.


    Organizational Affiliation

    From the Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Chimera protein of Outer membrane protein assembly factors BamA and BamB
A
645Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: bamB (yfgL), bamA (yaeT, yzzN, yzzY)
Find proteins for P77774 (Escherichia coli (strain K12))
Go to UniProtKB:  P77774
Find proteins for P0A940 (Escherichia coli (strain K12))
Go to UniProtKB:  P0A940
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.1 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.251 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 49.270α = 90.00
b = 91.410β = 92.85
c = 61.210γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious DiseasesUnited StatesR01 AI080709

Revision History 

  • Version 1.0: 2014-12-10
    Type: Initial release
  • Version 1.1: 2014-12-17
    Type: Database references
  • Version 1.2: 2015-02-04
    Type: Database references
  • Version 1.3: 2017-09-27
    Type: Author supporting evidence, Database references, Derived calculations, Source and taxonomy