4ZDX

Structure of OXA-51 beta-lactamase

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.160 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history. 


Literature

Structural Basis for Enhancement of Carbapenemase Activity in the OXA-51 Family of Class D beta-Lactamases.

Smith, C.A., Antunes, N.T., Stewart, N.K., Frase, H., Toth, M., Kantardjieff, K.A., Vakulenko, S.

(2015) ACS Chem Biol 10: 1791-1796

  • DOI: 10.1021/acschembio.5b00090
  • Primary Citation of Related Structures:  
    4ZDX

  • PubMed Abstract: 

    • Class D β-lactamases of Acinetobacter baumannii are enzymes of the utmost clinical importance, producing resistance to last resort carbapenem antibiotics. Although the OXA-51-like enzymes constitute the largest family of class D β-lactamases, they ar ...

    Class D β-lactamases of Acinetobacter baumannii are enzymes of the utmost clinical importance, producing resistance to last resort carbapenem antibiotics. Although the OXA-51-like enzymes constitute the largest family of class D β-lactamases, they are poorly studied and their importance in conferring carbapenem resistance is controversial. We present the detailed microbiological, kinetic, and structural characterization of the eponymous OXA-51 β-lactamase. Kinetic studies show that OXA-51 has low catalytic efficiency for carbapenems, primarily due to the low affinity of the enzyme for these substrates. Structural studies demonstrate that this low affinity results from the obstruction of the enzyme active site by the side chain of Trp222, which presents a transient steric barrier to an incoming carbapenem substrate. The Trp222Met substitution relieves this steric hindrance and elevates the affinity of the mutant enzyme for carbapenems by 10-fold, significantly increasing the levels of resistance to these antibiotics. The ability of OXA-51 to evolve into a robust carbapenemase as the result of a single amino acid substitution may, in the near future, elevate the ubiquitous enzymes of the OXA-51 family to the status of the most deleterious A. baumannii carbapenemases, with dire clinical consequences.

    Organizational Affiliation: 

    ‡Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.



Macromolecules
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(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Beta-lactamaseA274Acinetobacter baumanniiMutation(s): 0 
Gene Names: oxa-51, blaOXA, blaOXA-51, C2U32_04010
Find proteins for Q5QT35 (Acinetobacter baumannii)
Explore Q5QT35 
Go to UniProtKB:  Q5QT35
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TOE
Query on TOE
Download CCD File 
A
2-[2-(2-METHOXY-ETHOXY)-ETHOXY]-ETHOXYL
C7 H16 O4
JLGLQAWTXXGVEM-UHFFFAOYSA-N		 Ligand Interaction
GOL
Query on GOL
Download CCD File 
A
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N		 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
KCX
Query on KCX		AL-PEPTIDE LINKINGC7 H14 N2 O4LYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.160 
  • Space Group: I 4 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 131.111α = 90
b = 131.111β = 90
c = 67.525γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-06-17
    Type: Initial release
  • Version 1.1: 2015-09-02
    Changes: Database references