4RLB

Crystal structure of Acinetobacter baumannii CarO2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Small-Molecule Transport by CarO, an Abundant Eight-Stranded beta-Barrel Outer Membrane Protein from Acinetobacter baumannii.

Zahn, M.D'Agostino, T.Eren, E.Basle, A.Ceccarelli, M.van den Berg, B.

(2015) J.Mol.Biol. 427: 2329-2339

  • DOI: 10.1016/j.jmb.2015.03.016
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Outer membrane (OM) β-barrel proteins composed of 12-18 β-strands mediate cellular entry of small molecules in Gram-negative bacteria. Small OM proteins with barrels of 10 strands or less are not known to transport small molecules. CarO (carbapenem-a ...

    Outer membrane (OM) β-barrel proteins composed of 12-18 β-strands mediate cellular entry of small molecules in Gram-negative bacteria. Small OM proteins with barrels of 10 strands or less are not known to transport small molecules. CarO (carbapenem-associated outer membrane protein) from Acinetobacter baumannii is a small OM protein that has been implicated in the uptake of ornithine and carbapenem antibiotics. Here we report crystal structures of three isoforms of CarO. The structures are very similar and show a monomeric eight-stranded barrel lacking an open channel. CarO has a substantial extracellular domain resembling a glove that contains all the divergent residues between the different isoforms. Liposome swelling experiments demonstrate that full-length CarO and a "loop-less" truncation mutant mediate small-molecule uptake at low levels but that they are unlikely to mediate passage of carbapenem antibiotics. These results are confirmed by biased molecular dynamics simulations that allowed us to quantitatively model the transport of selected small molecules.


    Organizational Affiliation

    Institute for Cellular and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne, Tyne and Wear NE2 4HH, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbapenem-associated resistance protein
A, B
253Acinetobacter baumanniiMutation(s): 0 
Gene Names: carO
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: BETA-BARREL
Sub Group: 
Beta-Barrel Membrane Proteins: Monomeric/Dimeric
Protein: 
CarO outer membrane protein, isoform 1
Find proteins for Q5DL42 (Acinetobacter baumannii)
Go to UniProtKB:  Q5DL42
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.190 
  • Space Group: P 65 2 2
Unit Cell:
Length (Å)Angle (°)
a = 139.602α = 90.00
b = 139.602β = 90.00
c = 138.759γ = 120.00
Software Package:
Software NamePurpose
XDSdata scaling
MOLREPphasing
REFMACrefinement
GDAdata collection
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-04-22
    Type: Initial release
  • Version 1.1: 2015-06-24
    Type: Database references