2UYX

metallo-beta-lactamase (1BC2) single point mutant D120S


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.146 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Asp-120 Locates Zn2 for Optimal Metallo-Beta- Lactamase Activity

Larrull, L.I.Fabiane, S.M.Kowalski, J.M.Bennett, B.Sutton, B.J.Vila, A.J.

(2007) J.Biol.Chem. 282: 18276

  • DOI: 10.1074/jbc.M700742200

  • PubMed Abstract: 
  • Metallo-beta-lactamases are zinc-dependent hydrolases that inactivate beta-lactam antibiotics, rendering bacteria resistant to them. Asp-120 is fully conserved in all metallo-beta-lactamases and is central to catalysis. Several roles have been propos ...

    Metallo-beta-lactamases are zinc-dependent hydrolases that inactivate beta-lactam antibiotics, rendering bacteria resistant to them. Asp-120 is fully conserved in all metallo-beta-lactamases and is central to catalysis. Several roles have been proposed for Asp-120, but so far there is no agreed consensus. We generated four site-specifically substituted variants of the enzyme BcII from Bacillus cereus as follows: D120N, D120E, D120Q, and D120S. Replacement of Asp-120 by other residues with very different metal ligating capabilities severely impairs the lactamase activity without abolishing metal binding to the mutated site. A kinetic study of these mutants indicates that Asp-120 is not the proton donor, nor does it play an essential role in nucleophilic activation. Spectroscopic and crystallographic analysis of D120S BcII, the least active mutant bearing the weakest metal ligand in the series, reveals that this enzyme is able to accommodate a dinuclear center and that perturbations in the active site are limited to the Zn2 site. It is proposed that the role of Asp-120 is to act as a strong Zn2 ligand, locating this ion optimally for substrate binding, stabilization of the development of a partial negative charge in the beta-lactam nitrogen, and protonation of this atom by a zinc-bound water molecule.


    Organizational Affiliation

    Departamento de Química Biológica-Area Biofísica, Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BETA-LACTAMASE II
A
228Bacillus cereusGene Names: blm
EC: 3.5.2.6
Find proteins for P04190 (Bacillus cereus)
Go to UniProtKB:  P04190
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.146 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 53.389α = 90.00
b = 61.970β = 93.28
c = 69.573γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
REFMACrefinement
MOSFLMdata reduction
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-05-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance