1GA0

STRUCTURE OF THE E. CLOACAE GC1 BETA-LACTAMASE WITH A CEPHALOSPORIN SULFONE INHIBITOR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.181 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Inhibition of class C beta-lactamases: structure of a reaction intermediate with a cephem sulfone.

Crichlow, G.V.Nukaga, M.Doppalapudi, V.R.Buynak, J.D.Knox, J.R.

(2001) Biochemistry 40: 6233-6239


  • PubMed Abstract: 
  • The crystallographic structure of the Enterobacter cloacae GC1 extended-spectrum class C beta-lactamase, inhibited by a new 7-alkylidenecephalosporin sulfone, has been determined by X-ray diffraction at 100 K to a resolution of 1.6 A. The crystal str ...

    The crystallographic structure of the Enterobacter cloacae GC1 extended-spectrum class C beta-lactamase, inhibited by a new 7-alkylidenecephalosporin sulfone, has been determined by X-ray diffraction at 100 K to a resolution of 1.6 A. The crystal structure was solved by molecular replacement using the unliganded structure [Crichlow et al. (1999) Biochemistry 38, 10256-10261] and refined to a crystallographic R-factor equal to 0.183 (R(free) 0.208). Cryoquenching of the reaction of the sulfone with the enzyme produced an intermediate that is covalently bound via Ser64. After acylation of the beta-lactam ring, the dihydrothiazine dioxide ring opened with departure of the sulfinate. Nucleophilic attack of a side chain pyridine nitrogen atom on the C6 atom of the resultant imine yielded a bicyclic aromatic system which helps to stabilize the acyl enzyme to hydrolysis. A structural assist to this resonance stabilization is the positioning of the anionic sulfinate group between the probable catalytic base (Tyr150) and the acyl ester bond so as to block the approach of a potentially deacylating water molecule. Comparison of the liganded and unliganded protein structures showed that a major movement (up to 7 A) and refolding of part of the Omega-loop (215-224) accompanies the binding of the inhibitor. This conformational flexibility in the Omega-loop may form the basis of an extended-spectrum activity of class C beta-lactamases against modern cephalosporins.


    Organizational Affiliation

    Department of Molecular and Cell Biology, The University of Connecticut, Storrs, Connecticut 06269-3125, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BETA-LACTAMASE
A
364Enterobacter cloacaeEC: 3.5.2.6
Find proteins for Q59401 (Enterobacter cloacae)
Go to UniProtKB:  Q59401
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

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Download CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
DVR
Query on DVR

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Download CCD File 
A
3-(4-CARBAMOYL-1-CARBOXY-2-METHYLSULFONYL-BUTA-1,3-DIENYLAMINO)-INDOLIZINE-2-CARBOXYLIC ACID
C16 H15 N3 O6 S
ARSFRLAHCNFFCE-IBXIYJDRSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.181 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 77.000α = 90.00
b = 69.000β = 90.00
c = 62.500γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
DENZOdata reduction
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-06-06
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance
  • Version 1.3: 2011-11-16
    Type: Atomic model