4YFM

Class A beta-lactamase from Mycobacterium abscessus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.171 
  • R-Value Work: 0.143 
  • R-Value Observed: 0.144 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Hydrolysis of Clavulanate by Mycobacterium tuberculosis beta-Lactamase BlaC Harboring a Canonical SDN Motif.

Soroka, D.Li de la Sierra-Gallay, I.Dubee, V.Triboulet, S.van Tilbeurgh, H.Compain, F.Ballell, L.Barros, D.Mainardi, J.L.Hugonnet, J.E.Arthur, M.

(2015) Antimicrob Agents Chemother 59: 5714-5720

  • DOI: https://doi.org/10.1128/AAC.00598-15
  • Primary Citation of Related Structures:  
    4YFM

  • PubMed Abstract: 

    Combinations of β-lactams with clavulanate are currently being investigated for tuberculosis treatment. Since Mycobacterium tuberculosis produces a broad spectrum β-lactamase, BlaC, the success of this approach could be compromised by the emergence of clavulanate-resistant variants, as observed for inhibitor-resistant TEM variants in enterobacteria. Previous analyses based on site-directed mutagenesis of BlaC have led to the conclusion that this risk was limited. Here, we used a different approach based on determination of the crystal structure of β-lactamase BlaMAb of Mycobacterium abscessus, which efficiently hydrolyzes clavulanate. Comparison of BlaMAb and BlaC allowed for structure-assisted site-directed mutagenesis of BlaC and identification of the G(132)N substitution that was sufficient to switch the interaction of BlaC with clavulanate from irreversible inactivation to efficient hydrolysis. The substitution, which restored the canonical SDN motif (SDG→SDN), allowed for efficient hydrolysis of clavulanate, with a more than 10(4)-fold increase in k cat (0.41 s(-1)), without affecting the hydrolysis of other β-lactams. Mass spectrometry revealed that acylation of BlaC and of its G(132)N variant by clavulanate follows similar paths, involving sequential formation of two acylenzymes. Decarboxylation of the first acylenzyme results in a stable secondary acylenzyme in BlaC, whereas hydrolysis occurs in the G(132)N variant. The SDN/SDG polymorphism defines two mycobacterial lineages comprising rapidly and slowly growing species, respectively. Together, these results suggest that the efficacy of β-lactam-clavulanate combinations may be limited by the emergence of resistance. β-Lactams active without clavulanate, such as faropenem, should be prioritized for the development of new therapies.


  • Organizational Affiliation

    INSERM, UMR_S 1138, Centre de Recherche des Cordeliers, LRMA Equipe 12, Paris, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France Open Collaborative Model for Tuberculosis Lead Optimisation (ORCHID) Consortium.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Beta-lactamase
A, B
275Mycobacteroides abscessusMutation(s): 0 
Gene Names: LA62_14585
UniProt
Find proteins for B1MCI3 (Mycobacteroides abscessus (strain ATCC 19977 / DSM 44196 / CCUG 20993 / CIP 104536 / JCM 13569 / NCTC 13031 / TMC 1543 / L948))
Explore B1MCI3 
Go to UniProtKB:  B1MCI3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupB1MCI3
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.171 
  • R-Value Work: 0.143 
  • R-Value Observed: 0.144 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 36.49α = 90
b = 65.21β = 90.94
c = 107.42γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-07-22
    Type: Initial release
  • Version 1.1: 2015-08-26
    Changes: Database references
  • Version 1.2: 2024-01-10
    Changes: Data collection, Database references, Refinement description