1ZG6

TEM1 beta lactamase mutant S70G


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.176 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Structure of the wild-type TEM-1 beta-lactamase at 1.55 A and the mutant enzyme Ser70Ala at 2.1 A suggest the mode of noncovalent catalysis for the mutant enzyme.

Stec, B.Holtz, K.M.Wojciechowski, C.L.Kantrowitz, E.R.

(2005) Acta Crystallogr D Biol Crystallogr 61: 1072-1079

  • DOI: https://doi.org/10.1107/S0907444905014356
  • Primary Citation of Related Structures:  
    1ZG4, 1ZG6

  • PubMed Abstract: 

    One of the best-studied examples of a class A beta-lactamase is Escherichia coli TEM-1 beta-lactamase. In this class of enzymes, the active-site serine residue takes on the role of a nucleophile and carries out beta-lactam hydrolysis. Here, the structures of the wild-type and the S70G enzyme determined to 1.55 and 2.1 A, respectively, are presented. In contrast to the previously reported 1.8 A structure, the active site of the wild-type enzyme (1.55 A) structure does not contain sulfate and Ser70 appears to be in the deprotonated form. The X-ray crystal structure of the S70G mutant has an altered Ser130 side-chain conformation that influences the positions of water molecules in the active site. This change allows an additional water molecule to be positioned similarly to the serine hydroxyl in the wild-type enzyme. The structure of the mutant enzyme suggests that this water molecule can assume the role of an active-site nucleophile and carry out noncovalent catalysis. The drop in activity in the mutant enzyme is comparable to the drop observed in an analogous mutation of the nucleophilic serine in alkaline phosphatase, suggesting common chemical principles in the utilization of nucleophilic serine in the active site of different enzymes.


  • Organizational Affiliation

    Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, USA. bstec@utep.edu


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Beta-lactamase TEM286Escherichia coliMutation(s): 1 
Gene Names: bla
EC: 3.5.2.6
UniProt
Find proteins for P62593 (Escherichia coli)
Explore P62593 
Go to UniProtKB:  P62593
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP62593
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.176 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 41.99α = 90
b = 62.65β = 90
c = 89.49γ = 90
Software Package:
Software NamePurpose
SDMSdata collection
SDMSdata reduction
X-PLORmodel building
SHELXL-97refinement
SDMSdata scaling
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-05-17
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-10-20
    Changes: Database references
  • Version 1.4: 2023-08-23
    Changes: Data collection, Refinement description