1MXO | pdb_00001mxo

AmpC beta-lactamase in complex with an m.carboxyphenylglycylboronic acid bearing the cephalothin R1 side chain


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.83 Å
  • R-Value Free: 
    0.214 (Depositor), 0.207 (DCC) 
  • R-Value Work: 
    0.187 (Depositor), 0.180 (DCC) 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history

Literature

Nanomolar inhibitors of AmpC beta-lactamase.

Morandi, F.Caselli, E.Morandi, S.Focia, P.J.Blazquez, J.Shoichet, B.K.Prati, F.

(2003) J Am Chem Soc 125: 685-695

  • DOI: https://doi.org/10.1021/ja0288338
  • Primary Citation Related Structures: 
    1MXO, 1MY8

  • PubMed Abstract: 

    beta-lactamases are the most widespread resistance mechanism to beta-lactam antibiotics, such as the penicillins and the cephalosporins. In an effort to combat these enzymes, a combination of stereoselective organic synthesis, enzymology, microbiology, and X-ray crystallography was used to design and evaluate new carboxyphenyl-glycylboronic acid transition-state analogue inhibitors of the class C beta-lactamase AmpC. The new compounds improve inhibition by over 2 orders of magnitude compared to analogous glycylboronic acids, with K(i) values as low as 1 nM. On the basis of the differential binding of different analogues, the introduced carboxylate alone contributes about 2.1 kcal/mol in affinity. This carboxylate corresponds to the ubiquitous C3(4)' carboxylate of beta-lactams, and this energy represents the first thermodynamic measurement of the importance of this group in molecular recognition by class C beta-lactamases. The structures of AmpC in complex with two of these inhibitors were determined by X-ray crystallography at 1.72 and 1.83 A resolution. These structures suggest a structural basis for the high affinity of the new compounds and provide templates for further design. The highest affinity inhibitor was 5 orders of magnitude more selective for AmpC than for characteristic serine proteases, such as chymotrypsin. This inhibitor reversed the resistance of clinical pathogens to the third generation cephalosporin ceftazidime; it may serve as a lead compound for drug discovery to combat bacterial resistance to beta-lactam antibiotics.


  • Organizational Affiliation
    • Department of Pharmaceutical Chemistry, University of California, San Francisco, Mission Bay Genentech Hall, 600 16th Street, Mail Box 2240, 94143, USA.

Macromolecule Content 

  • Total Structure Weight: 79.91 kDa 
  • Atom Count: 6,118 
  • Modeled Residue Count: 716 
  • Deposited Residue Count: 716 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Beta-lactamase
A, B
358Escherichia coliMutation(s): 0 
Gene Names: ampc
EC: 3.5.2.6
UniProt
Find proteins for P00811 (Escherichia coli (strain K12))
Explore P00811 
Go to UniProtKB:  P00811
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00811
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.83 Å
  • R-Value Free:  0.214 (Depositor), 0.207 (DCC) 
  • R-Value Work:  0.187 (Depositor), 0.180 (DCC) 
Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 117.957α = 90
b = 77.488β = 115.78
c = 96.906γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
CNSrefinement
CNSphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-03-04
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-10-30
    Changes: Data collection, Database references, Derived calculations, Refinement description, Structure summary