6O9W

Crystal structure of Staphylococcus aureus BlaR1 antibiotic-sensor domain in complex with avibactam


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 

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This is version 1.2 of the entry. See complete history


Literature

Structural analysis of avibactam-mediated activation of the bla and mec divergons in methicillin-resistant Staphylococcus aureus .

Alexander, J.A.N.Radaeva, M.King, D.T.Chambers, H.F.Cherkasov, A.Chatterjee, S.S.Strynadka, N.C.J.

(2020) J Biol Chem 295: 10870-10884

  • DOI: https://doi.org/10.1074/jbc.RA120.013029
  • Primary Citation of Related Structures:  
    6O9S, 6O9W

  • PubMed Abstract: 

    Methicillin-resistant Staphylococcus aureus (MRSA) infections cause significant mortality and morbidity globally. MRSA resistance to β-lactam antibiotics is mediated by two divergons that control levels of a β-lactamase, PC1, and a penicillin-binding protein poorly acylated by β-lactam antibiotics, PBP2a. Expression of genes encoding these proteins is controlled by two integral membrane proteins, BlaR1 and MecR1, which both have an extracellular β-lactam-binding sensor domain. Here, we solved the X-ray crystallographic structures of the BlaR1 and MecR1 sensor domains in complex with avibactam, a diazabicyclooctane β-lactamase inhibitor at 1.6-2.0 Å resolution. Additionally, we show that S. aureus SF8300, a clinically relevant strain from the USA300 clone of MRSA, responds to avibactam by up-regulating the expression of the blaZ and pbp2a antibiotic-resistance genes, encoding PC1 and PBP2a, respectively. The BlaR1-avibactam structure of the carbamoyl-enzyme intermediate revealed that avibactam is bound to the active-site serine in two orientations ∼180° to each other. Although a physiological role of the observed alternative pose remains to be validated, our structural results hint at the presence of a secondary sulfate-binding pocket that could be exploited in the design of future inhibitors of BlaR1/MecR1 sensor domains or the structurally similar class D β-lactamases. The MecR1-avibactam structure adopted a singular avibactam orientation similar to one of the two states observed in the BlaR1-avibactam structure. Given avibactam up-regulates expression of blaZ and pbp2a antibiotic resistance genes, we suggest further consideration and research is needed to explore what effects administering β-lactam-avibactam combinations have on treating MRSA infections.


  • Organizational Affiliation

    Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Regulatory protein BlaR1
A, B
259Staphylococcus aureusMutation(s): 0 
Gene Names: blaR1
UniProt
Find proteins for P18357 (Staphylococcus aureus)
Explore P18357 
Go to UniProtKB:  P18357
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP18357
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
NXL
Query on NXL

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
(2S,5R)-1-formyl-5-[(sulfooxy)amino]piperidine-2-carboxamide
C7 H13 N3 O6 S
WJDGWXPPFHLLNL-RITPCOANSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 53.355α = 90
b = 92.647β = 104.57
c = 56.472γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
Aimlessdata scaling
PHASERphasing
PDB_EXTRACTdata extraction

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Canadian Institutes of Health Research (CIHR)Canada--

Revision History  (Full details and data files)

  • Version 1.0: 2020-06-10
    Type: Initial release
  • Version 1.1: 2020-10-07
    Changes: Database references
  • Version 1.2: 2023-10-11
    Changes: Data collection, Database references, Refinement description