3CMZ

TEM-1 Class-A beta-lactamase L201P mutant apo structure


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.92 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.196 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Genetic and structural characterization of an L201P global suppressor substitution in TEM-1 beta-lactamase

Marciano, D.C.Pennington, J.M.Wang, X.Wang, J.Chen, Y.Thomas, V.L.Shoichet, B.K.Palzkill, T.

(2008) J.Mol.Biol. 384: 151-164

  • DOI: 10.1016/j.jmb.2008.09.009

  • PubMed Abstract: 
  • TEM-1 beta-lactamase confers bacterial resistance to penicillin antibiotics and has acquired mutations that permit the enzyme to hydrolyze extended-spectrum cephalosporins or to avoid inactivation by beta-lactamase inhibitors. However, many of these ...

    TEM-1 beta-lactamase confers bacterial resistance to penicillin antibiotics and has acquired mutations that permit the enzyme to hydrolyze extended-spectrum cephalosporins or to avoid inactivation by beta-lactamase inhibitors. However, many of these substitutions have been shown to reduce activity against penicillin antibiotics and/or result in loss of stability for the enzyme. In order to gain more information concerning the tradeoffs associated with active site substitutions, a genetic selection was used to find second site mutations that partially restore ampicillin resistance levels conferred by an R244A active site TEM-1 beta-lactamase mutant. An L201P substitution distant from the active site that enhanced ampicillin resistance levels and increased protein expression levels of the R244A TEM-1 mutant was identified. The L201P substitution also increases the ampicillin resistance levels and restores expression levels of a poorly expressed TEM-1 mutant with a core-disrupting substitution. In vitro thermal denaturation of purified protein indicated that the L201P mutation increases the T(m) value of the TEM-1 enzyme. The X-ray structure of the L201P TEM-1 mutant was determined to gain insight into the increase in enzyme stability. The proline substitution occurs at the N-terminus of an alpha-helix and may stabilize the enzyme by reducing the helix dipole, as well as by lowering the conformational entropy cost of folding due to the reduced number of conformations available in the unfolded state. Collectively, the data suggest that L201P promotes tolerance of some deleterious TEM-1 mutations by enhancing the protein stability of these mutants.


    Organizational Affiliation

    Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Beta-lactamase TEM
A
263Escherichia coliMutation(s): 1 
Gene Names: bla, blaT-3, blaT-4, blaT-5, blaT-6
EC: 3.5.2.6
Find proteins for P62593 (Escherichia coli)
Go to UniProtKB:  P62593
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
A
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.92 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.196 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 41.218α = 90.00
b = 59.140β = 90.00
c = 87.802γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
DENZOdata reduction
REFMACrefinement
EPMRphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-11-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance