6PWM

ADC-7 in complex with Beta-lactam antibiotic ceftazidime


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.213 
  • R-Value Observed: 0.215 

Starting Model: experimental
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This is version 1.3 of the entry. See complete history


Literature

Structural Insights into Inhibition of the Acinetobacter-Derived Cephalosporinase ADC-7 by Ceftazidime and Its Boronic Acid Transition State Analog.

Curtis, B.N.Smolen, K.A.Barlow, S.J.Caselli, E.Prati, F.Taracila, M.A.Bonomo, R.A.Wallar, B.J.Powers, R.A.

(2020) Antimicrob Agents Chemother 64

  • DOI: https://doi.org/10.1128/AAC.01183-20
  • Primary Citation of Related Structures:  
    6PWL, 6PWM

  • PubMed Abstract: 

    Extended-spectrum class C β-lactamases have evolved to rapidly inactivate expanded-spectrum cephalosporins, a class of antibiotics designed to be resistant to hydrolysis by β-lactamase enzymes. To better understand the mechanism by which A cinetobacter- d erived c ephalosporinase-7 (ADC-7), a chromosomal AmpC enzyme, hydrolyzes these molecules, we determined the X-ray crystal structure of ADC-7 in an acyl-enzyme complex with the cephalosporin ceftazidime (2.40 Å) as well as in complex with a boronic acid transition state analog inhibitor that contains the R1 side chain of ceftazidime (1.67 Å). In the acyl-enzyme complex, the carbonyl oxygen is situated in the oxyanion hole where it makes key stabilizing interactions with the main chain nitrogens of Ser64 and Ser315. The boronic acid O1 hydroxyl group is similarly positioned in this area. Conserved residues Gln120 and Asn152 form hydrogen bonds with the amide group of the R1 side chain in both complexes. These complexes represent two steps in the hydrolysis of expanded-spectrum cephalosporins by ADC-7 and offer insight into the inhibition of ADC-7 by ceftazidime through displacement of the deacylating water molecule as well as blocking its trajectory to the acyl carbonyl carbon. In addition, the transition state analog inhibitor, LP06, was shown to bind with high affinity to ADC-7 ( K i , 50 nM) and was able to restore ceftazidime susceptibility, offering the potential for optimization efforts of this type of inhibitor.


  • Organizational Affiliation

    Department of Chemistry, Grand Valley State University, Allendale, Michigan, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Beta-lactamase
A, B, C, D
361Acinetobacter baumanniiMutation(s): 0 
EC: 3.5.2.6
UniProt
Find proteins for Q6DRA1 (Acinetobacter baumannii)
Explore Q6DRA1 
Go to UniProtKB:  Q6DRA1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ6DRA1
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.213 
  • R-Value Observed: 0.215 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 92.261α = 90
b = 81.661β = 112.61
c = 105.22γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
XSCALEdata scaling
PHASERphasing
Cootmodel building

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)United StatesR01 AI072219

Revision History  (Full details and data files)

  • Version 1.0: 2020-10-21
    Type: Initial release
  • Version 1.1: 2020-12-02
    Changes: Database references
  • Version 1.2: 2023-10-11
    Changes: Data collection, Database references, Refinement description
  • Version 1.3: 2024-10-16
    Changes: Structure summary