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 

wwPDB Validation   3D Report Full Report


This is version 1.1 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: 10.1128/AAC.01183-20
  • Primary Citation of Related Structures:  
    6PWM, 6PWL

  • 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 ...

    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 robert.bonomo@va.gov wallarb@gvsu.edu powersra@gvsu.edu.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Beta-lactamaseA, B, C, D361Acinetobacter baumanniiMutation(s): 0 
EC: 3.5.2.6
UniProt
Find proteins for Q6DRA1 (Acinetobacter baumannii)
Explore Q6DRA1 
Go to UniProtKB:  Q6DRA1
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CAZ
Query on CAZ

Download Ideal Coordinates CCD File 
E [auth A], G [auth B], H [auth C], I [auth D]ACYLATED CEFTAZIDIME
C17 H19 N5 O7 S2
VEHPZKIFULQYFS-BZXVCXBKSA-N
 Ligand Interaction
GLY
Query on GLY

Download Ideal Coordinates CCD File 
F [auth A]GLYCINE
C2 H5 N O2
DHMQDGOQFOQNFH-UHFFFAOYSA-N
 Ligand Interaction
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

View Full Validation Report



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