3NI9

GES-2 carbapenemase apo form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.222 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Kinetic and structural requirements for carbapenemase activity in GES-type beta-lactamases.

Stewart, N.K.Smith, C.A.Frase, H.Black, D.J.Vakulenko, S.B.

(2015) Biochemistry 54: 588-597

  • DOI: https://doi.org/10.1021/bi501052t
  • Primary Citation of Related Structures:  
    3NI9, 4QU3

  • PubMed Abstract: 

    Carbapenems are the last resort antibiotics for treatment of life-threatening infections. The GES β-lactamases are important contributors to carbapenem resistance in clinical bacterial pathogens. A single amino acid difference at position 170 of the GES-1, GES-2, and GES-5 enzymes is responsible for the expansion of their substrate profile to include carbapenem antibiotics. This highlights the increasing need to understand the mechanisms by which the GES β-lactamases function to aid in development of novel therapeutics. We demonstrate that the catalytic efficiency of the enzymes with carbapenems meropenem, ertapenem, and doripenem progressively increases (100-fold) from GES-1 to -5, mainly due to an increase in the rate of acylation. The data reveal that while acylation is rate limiting for GES-1 and GES-2 for all three carbapenems, acylation and deacylation are indistinguishable for GES-5. The ertapenem-GES-2 crystal structure shows that only the core structure of the antibiotic interacts with the active site of the GES-2 β-lactamase. The identical core structures of ertapenem, doripenem, and meropenem are likely responsible for the observed similarities in the kinetics with these carbapenems. The lack of a methyl group in the core structure of imipenem may provide a structural rationale for the increase in turnover of this carbapenem by the GES β-lactamases. Our data also show that in GES-2 an extensive hydrogen-bonding network between the acyl-enzyme complex and the active site water attenuates activation of this water molecule, which results in poor deacylation by this enzyme.


  • Organizational Affiliation

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


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Beta-lactamase GES-2
A, B
269Pseudomonas aeruginosaMutation(s): 0 
Gene Names: bla GES-2
EC: 3.5.2.6
UniProt
Find proteins for Q93F76 (Pseudomonas aeruginosa)
Explore Q93F76 
Go to UniProtKB:  Q93F76
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ93F76
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.222 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 76.46α = 90
b = 80.54β = 90
c = 87.89γ = 90
Software Package:
Software NamePurpose
Blu-Icedata collection
MOLREPphasing
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-02-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-06-21
    Changes: Database references
  • Version 1.3: 2023-09-06
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 1.4: 2024-11-06
    Changes: Structure summary