4EV4

Crystal structure of serratia fonticola carbapenemase SFC-1 E166A mutant with the acylenzyme intermediate of meropenem


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.30 Å
  • R-Value Free: 0.155 
  • R-Value Work: 0.114 
  • R-Value Observed: 0.116 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history

Re-refinement Note

A newer entry is available that reflects an alternative modeling of the original data: 6DMH


Literature

The basis for carbapenem hydrolysis by class A beta-lactamases: a combined investigation using crystallography and simulations.

Fonseca, F.Chudyk, E.I.van der Kamp, M.W.Correia, A.Mulholland, A.J.Spencer, J.

(2012) J Am Chem Soc 134: 18275-18285

  • DOI: https://doi.org/10.1021/ja304460j
  • Primary Citation of Related Structures:  
    4EQI, 4EUZ, 4EV4

  • PubMed Abstract: 

    Carbapenems are the most potent β-lactam antibiotics and key drugs for treating infections by Gram-negative bacteria. In such organisms, β-lactam resistance arises principally from β-lactamase production. Although carbapenems escape the activity of most β-lactamases, due in the class A enzymes to slow deacylation of the covalent acylenzyme intermediate, carbapenem-hydrolyzing class A β-lactamases are now disseminating in clinically relevant bacteria. The reasons why carbapenems are substrates for these enzymes, but inhibit other class A β-lactamases, remain to be fully established. Here, we present crystal structures of the class A carbapenemase SFC-1 from Serratia fonticola and of complexes of its Ser70 Ala (Michaelis) and Glu166 Ala (acylenzyme) mutants with the carbapenem meropenem. These are the first crystal structures of carbapenem complexes of a class A carbapenemase. Our data reveal that, in the SFC-1 acylenzyme complex, the meropenem 6α-1R-hydroxyethyl group interacts with Asn132, but not with the deacylating water molecule. Molecular dynamics simulations indicate that this mode of binding occurs in both the Michaelis and acylenzyme complexes of wild-type SFC-1. In carbapenem-inhibited class A β-lactamases, it is proposed that the deacylating water molecule is deactivated by interaction with the carbapenem 6α-1R-hydroxyethyl substituent. Structural comparisons with such enzymes suggest that in SFC-1 subtle repositioning of key residues (Ser70, Ser130, Asn132 and Asn170) enlarges the active site, permitting rotation of the carbapenem 6α-1R-hydroxyethyl group and abolishing this contact. Our data show that SFC-1, and by implication other such carbapenem-hydrolyzing enzymes, uses Asn132 to orient bound carbapenems for efficient deacylation and prevent their interaction with the deacylating water molecule.


  • Organizational Affiliation

    School of Cellular and Molecular Medicine, University of Bristol, Medical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom. maria.fonseca@ibmc.up.pt


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Carbapenem-hydrolizing beta-lactamase SFC-1283Serratia fonticolaMutation(s): 1 
Gene Names: BLASFC-1SFC-1
EC: 3.5.2.6
UniProt
Find proteins for Q6JP75 (Serratia fonticola)
Explore Q6JP75 
Go to UniProtKB:  Q6JP75
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ6JP75
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.30 Å
  • R-Value Free: 0.155 
  • R-Value Work: 0.114 
  • R-Value Observed: 0.116 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.185α = 90
b = 61.955β = 90
c = 79.127γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
PHASERphasing
SHELXL-97refinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-05-23
    Type: Initial release
  • Version 1.1: 2013-08-28
    Changes: Database references
  • Version 1.2: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description, Structure summary