1CI9

DFP-INHIBITED ESTERASE ESTB FROM BURKHOLDERIA GLADIOLI


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.176 

Starting Model: other
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This is version 1.6 of the entry. See complete history


Literature

EstB from Burkholderia gladioli: a novel esterase with a beta-lactamase fold reveals steric factors to discriminate between esterolytic and beta-lactam cleaving activity

Wagner, U.G.Petersen, E.I.Schwab, H.Kratky, C.

(2002) Protein Sci 11: 467-478

  • DOI: https://doi.org/10.1110/ps.33002
  • Primary Citation of Related Structures:  
    1CI8, 1CI9

  • PubMed Abstract: 

    Esterases form a diverse class of enzymes of largely unknown physiological role. Because many drugs and pesticides carry ester functions, the hydrolysis of such compounds forms at least one potential biological function. Carboxylesterases catalyze the hydrolysis of short chain aliphatic and aromatic carboxylic ester compounds. Esterases, D-alanyl-D-alanine-peptidases (DD-peptidases) and beta-lactamases can be grouped into two distinct classes of hydrolases with different folds and topologically unrelated catalytic residues, the one class comprising of esterases, the other one of beta-lactamases and DD-peptidases. The chemical reactivities of esters and beta-lactams towards hydrolysis are quite similar, which raises the question of which factors prevent esterases from displaying beta-lactamase activity and vice versa. Here we describe the crystal structure of EstB, an esterase isolated from Burkholderia gladioli. It shows the protein to belong to a novel class of esterases with homology to Penicillin binding proteins, notably DD-peptidase and class C beta-lactamases. Site-directed mutagenesis and the crystal structure of the complex with diisopropyl-fluorophosphate suggest Ser75 within the "beta-lactamase" Ser-x-x-Lys motif to act as catalytic nucleophile. Despite its structural homology to beta-lactamases, EstB shows no beta-lactamase activity. Although the nature and arrangement of active-site residues is very similar between EstB and homologous beta-lactamases, there are considerable differences in the shape of the active site tunnel. Modeling studies suggest steric factors to account for the enzyme's selectivity for ester hydrolysis versus beta-lactam cleavage.


  • Organizational Affiliation

    Institut für Chemie, Strukturbiologie, Karl-Franzens-Universität, A-8010 Graz, Austria. Wagner@Uni-Graz.at


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (CARBOXYLESTERASE)
A, B
392Burkholderia gladioliMutation(s): 0 
Gene Names: ESTB
EC: 3.1.1.1 (PDB Primary Data), 3.1.1 (UniProt)
UniProt
Find proteins for Q9KX40 (Burkholderia gladioli)
Explore Q9KX40 
Go to UniProtKB:  Q9KX40
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9KX40
Sequence Annotations
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.176 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 83.444α = 90
b = 83.444β = 90
c = 194.576γ = 120
Software Package:
Software NamePurpose
AMoREphasing
SHELXL-97refinement
DENZOdata reduction
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-12-12
    Type: Initial release
  • Version 1.1: 2008-04-26
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-04
    Changes: Refinement description
  • Version 1.4: 2019-11-27
    Changes: Data collection, Database references, Derived calculations
  • Version 1.5: 2023-12-27
    Changes: Data collection, Database references, Derived calculations
  • Version 1.6: 2024-04-03
    Changes: Refinement description