4ECL

Crystal structure of the cytoplasmic domain of vancomycin resistance serine racemase VanTg


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.02 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.182 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural and Functional Adaptation of Vancomycin Resistance VanT Serine Racemases.

Meziane-Cherif, D.Stogios, P.J.Evdokimova, E.Egorova, O.Savchenko, A.Courvalin, P.

(2015) mBio 6: e00806-e00806

  • DOI: 10.1128/mBio.00806-15
  • Primary Citation of Related Structures:  
    4ECL

  • PubMed Abstract: 
  • Vancomycin resistance in Gram-positive bacteria results from the replacement of the D-alanyl-D-alanine target of peptidoglycan precursors with D-alanyl-D-lactate or D-alanyl-D-serine (D-Ala-D-Ser), to which vancomycin has low binding affinity. VanT is one of the proteins required for the production of D-Ala-D-Ser-terminating precursors by converting L-Ser to D-Ser ...

    Vancomycin resistance in Gram-positive bacteria results from the replacement of the D-alanyl-D-alanine target of peptidoglycan precursors with D-alanyl-D-lactate or D-alanyl-D-serine (D-Ala-D-Ser), to which vancomycin has low binding affinity. VanT is one of the proteins required for the production of D-Ala-D-Ser-terminating precursors by converting L-Ser to D-Ser. VanT is composed of two domains, an N-terminal membrane-bound domain, likely involved in L-Ser uptake, and a C-terminal cytoplasmic catalytic domain which is related to bacterial alanine racemases. To gain insight into the molecular function of VanT, the crystal structure of the catalytic domain of VanTG from VanG-type resistant Enterococcus faecalis BM4518 was determined. The structure showed significant similarity to type III pyridoxal 5'-phosphate (PLP)-dependent alanine racemases, which are essential for peptidoglycan synthesis. Comparative structural analysis between VanTG and alanine racemases as well as site-directed mutagenesis identified three specific active site positions centered around Asn696 which are responsible for the L-amino acid specificity. This analysis also suggested that VanT racemases evolved from regular alanine racemases by acquiring additional selectivity toward serine while preserving that for alanine. The 4-fold-lower relative catalytic efficiency of VanTG against L-Ser versus L-Ala implied that this enzyme relies on its membrane-bound domain for L-Ser transport to increase the overall rate of d-Ser production. These findings illustrate how vancomycin pressure selected for molecular adaptation of a housekeeping enzyme to a bifunctional enzyme to allow for peptidoglycan remodeling, a strategy increasingly observed in antibiotic-resistant bacteria.


    Organizational Affiliation

    Institut Pasteur, Unité des Agents Antibactériens, Paris, France pcourval@pasteur.fr alexei.savchenko@utoronto.ca.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Serine racemaseABCD374Enterococcus faecalisMutation(s): 0 
Gene Names: vanTG
EC: 5.1.1.1
Find proteins for Q6WRY3 (Enterococcus faecalis)
Explore Q6WRY3 
Go to UniProtKB:  Q6WRY3
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download CCD File 
A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CL
Query on CL

Download CCD File 
A, B, C, D
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A,B,C,DL-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.682α = 90
b = 82.341β = 90.14
c = 117.468γ = 90
Software Package:
Software NamePurpose
HKL-3000data collection
PHENIXmodel building
PHENIXrefinement
HKL-3000data reduction
HKL-3000data scaling
PHENIXphasing

Structure Validation

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Entry History 

Revision History 

  • Version 1.0: 2012-04-18
    Type: Initial release
  • Version 1.1: 2016-06-01
    Changes: Database references