Crystal structure of ADC-1 beta-lactamase

Experimental Data Snapshot

  • Resolution: 1.20 Å
  • R-Value Free: 0.185 
  • R-Value Work: 0.156 
  • R-Value Observed: 0.157 

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Structure of the extended-spectrum class C beta-lactamase ADC-1 from Acinetobacter baumannii.

Bhattacharya, M.Toth, M.Antunes, N.T.Smith, C.A.Vakulenko, S.B.

(2014) Acta Crystallogr D Biol Crystallogr 70: 760-771

  • DOI: https://doi.org/10.1107/S1399004713033014
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    ADC-type class C β-lactamases comprise a large group of enzymes that are encoded by genes located on the chromosome of Acinetobacter baumannii, a causative agent of serious bacterial infections. Overexpression of these enzymes renders A. baumannii resistant to various β-lactam antibiotics and thus severely compromises the ability to treat infections caused by this deadly pathogen. Here, the high-resolution crystal structure of ADC-1, the first member of this clinically important family of antibiotic-resistant enzymes, is reported. Unlike the narrow-spectrum class C β-lactamases, ADC-1 is capable of producing resistance to the expanded-spectrum cephalosporins, rendering them inactive against A. baumannii. The extension of the substrate profile of the enzyme is likely to be the result of structural differences in the R2-loop, primarily the deletion of three residues and subsequent rearrangement of the A10a and A10b helices. These structural rearrangements result in the enlargement of the R2 pocket of ADC-1, allowing it to accommodate the bulky R2 substituents of the third-generation cephalosporins, thus enhancing the catalytic efficiency of the enzyme against these clinically important antibiotics.

  • Organizational Affiliation

    Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
361Acinetobacter baumanniiMutation(s): 0 
Gene Names: ampC
Find proteins for Q9L4R5 (Acinetobacter baumannii)
Explore Q9L4R5 
Go to UniProtKB:  Q9L4R5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9L4R5
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.20 Å
  • R-Value Free: 0.185 
  • R-Value Work: 0.156 
  • R-Value Observed: 0.157 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 43.073α = 90
b = 182.151β = 98.8
c = 50.373γ = 90
Software Package:
Software NamePurpose
Blu-Icedata collection
XDSdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-03-12
    Type: Initial release
  • Version 1.1: 2014-09-24
    Changes: Database references
  • Version 1.2: 2024-02-28
    Changes: Data collection, Database references, Derived calculations