2JKS

Crystal structure of the the bradyzoite specific antigen BSR4 from toxoplasma gondii.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.238 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Characterization of the Bradyzoite Surface Antigen (Bsr4) from Toxoplasma Gondii, a Unique Addition to the Surface Antigen Glycoprotein 1-Related Superfamily.

Crawford, J.Grujic, O.Bruic, E.Czjzek, M.Grigg, M.E.Boulanger, M.J.

(2009) J.Biol.Chem. 284: 9192

  • DOI: 10.1074/jbc.M808714200

  • PubMed Abstract: 
  • Toxoplasma gondii is an obligate intracellular protozoan parasite that infects nearly one-third of the human population. The success of T. gondii is based on its complex life cycle; a lytic tachyzoite form disseminates infection, whereas an encysted ...

    Toxoplasma gondii is an obligate intracellular protozoan parasite that infects nearly one-third of the human population. The success of T. gondii is based on its complex life cycle; a lytic tachyzoite form disseminates infection, whereas an encysted bradyzoite form establishes a latent, chronic infection. Persistence and transmissibility is central to the survival of the parasite and is, in part, mediated by a family of antigenically distinct surface antigen glycoprotein (SAG)-related sequences (SRS) adhesins that play a dual role in host cell attachment and host immune evasion. More than 160 members of the SRS family have been identified with only the tachyzoite-expressed SAG1 structurally characterized. Here we report the first structural description of the bradyzoite adhesin BSR4 using x-ray crystallography and small angle x-ray scattering. The 1.90-A crystal structure of BSR4 reveals an architecture comprised of tandem beta sandwich domains organized in a head to tail fashion with the N-terminal domain responsible for dimer formation. A restructured topology in BSR4 results in a ligand-binding site that is significantly reorganized in both structure and chemistry relative to SAG1, consistent with BSR4 binding a distinct physiological ligand. The small angle x-ray scattering solution structure of BSR4 highlights a potentially important structural role for the interdomain polymorphic linker that imparts significant flexibility that may promote structural adaptation during ligand binding. This study reveals an unexpected level of structural diversity within the SRS superfamily and provides important insight into the role of these virulence factors.


    Organizational Affiliation

    Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BRADYZOITE SURFACE ANTIGEN BSR4
A
315Toxoplasma gondiiMutation(s): 0 
Gene Names: BSR4
Find proteins for Q95NL6 (Toxoplasma gondii)
Go to UniProtKB:  Q95NL6
Small Molecules
Ligands 1 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
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.238 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 92.050α = 90.00
b = 92.050β = 90.00
c = 98.310γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
CrystalCleardata reduction
CrystalCleardata scaling
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-02-03
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance
  • Version 1.2: 2017-07-05
    Type: Data collection