2P5T

Molecular and structural characterization of the PezAT chromosomal toxin-antitoxin system of the human pathogen Streptococcus pneumoniae


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.2 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.214 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Molecular and Structural Characterization of the PezAT Chromosomal Toxin-Antitoxin System of the Human Pathogen Streptococcus pneumoniae.

Khoo, S.K.Loll, B.Chan, W.T.Shoeman, R.L.Ngoo, L.Yeo, C.C.Meinhart, A.

(2007) J.Biol.Chem. 282: 19606-19618

  • DOI: 10.1074/jbc.M701703200

  • PubMed Abstract: 
  • The chromosomal pezT gene of the Gram-positive pathogen Streptococcus pneumoniae encodes a protein that is homologous to the zeta toxin of the Streptococcus pyogenes plasmid pSM19035-encoded epsilon-zeta toxin-antitoxin system. Overexpression of pezT ...

    The chromosomal pezT gene of the Gram-positive pathogen Streptococcus pneumoniae encodes a protein that is homologous to the zeta toxin of the Streptococcus pyogenes plasmid pSM19035-encoded epsilon-zeta toxin-antitoxin system. Overexpression of pezT in Escherichia coli led to severe growth inhibition from which the bacteria recovered approximately 3 h after induction of expression. The toxicity of PezT was counteracted by PezA, which is encoded immediately upstream of pezT and shares weak sequence similarities in the C-terminal region with the epsilon antitoxin. The pezAT genes form a bicistronic operon that is co-transcribed from a sigma(70)-like promoter upstream of pezA and is negatively autoregulated with PezA functioning as a transcriptional repressor and PezT as a co-repressor. Both PezA and the non-toxic PezA(2)PezT(2) protein complex bind to a palindrome sequence that overlaps the promoter. This differs from the epsilon-zeta system in which epsilon functions solely as the antitoxin and transcriptional regulation is carried out by another protein designated omega. Results from site-directed mutagenesis experiments demonstrated that the toxicity of PezT is dependent on a highly conserved phosphoryltransferase active site and an ATP/GTP nucleotide binding site. In the PezA(2)PezT(2) complex, PezA neutralizes the toxicity of PezT by blocking the nucleotide binding site through steric hindrance.


    Organizational Affiliation

    Department of Biomolecular Mechanisms, Max-Planck-Institute for Medical Research, 69120 Heidelberg, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
fragment of PezA helix-turn-helix motif
X
33N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Putative transcriptional regulator PezA
A, C, E, G
158Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4)Mutation(s): 0 
Gene Names: pezA
Find proteins for Q97QZ2 (Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4))
Go to UniProtKB:  Q97QZ2
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
PezT
B, D, F, H
253Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4)Mutation(s): 0 
Gene Names: pezT
Find proteins for Q97QZ1 (Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4))
Go to UniProtKB:  Q97QZ1
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
UNK
Query on UNK
X
L-PEPTIDE LINKINGC4 H9 N O2

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.2 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.214 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 80.520α = 90.00
b = 102.860β = 90.00
c = 254.440γ = 90.00
Software Package:
Software NamePurpose
XDSdata scaling
REFMACrefinement
XDSdata reduction
SHELXDphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2007-03-16 
  • Released Date: 2007-05-15 
  • Deposition Author(s): Loll, B., Meinhart, A.

Revision History 

  • Version 1.0: 2007-05-15
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Source and taxonomy, Version format compliance