1VSG

2.9 ANGSTROMS RESOLUTION STRUCTURE OF THE N-TERMINAL DOMAIN OF A VARIANT SURFACE GLYCOPROTEIN FROM TRYPANOSOMA BRUCEI


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Work: 0.220 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

2.9 A resolution structure of the N-terminal domain of a variant surface glycoprotein from Trypanosoma brucei.

Freymann, D.Down, J.Carrington, M.Roditi, I.Turner, M.Wiley, D.

(1990) J.Mol.Biol. 216: 141-160

  • DOI: 10.1016/S0022-2836(05)80066-X

  • PubMed Abstract: 
  • The variant surface glycoprotein (VSG) of Trypanosoma brucei forms a coat on the surface of the parasite; by the expression of a series of antigenically distinct VSGs in the surface coat the parasite escapes the host immune response. The 2.9 A resolu ...

    The variant surface glycoprotein (VSG) of Trypanosoma brucei forms a coat on the surface of the parasite; by the expression of a series of antigenically distinct VSGs in the surface coat the parasite escapes the host immune response. The 2.9 A resolution crystal structure of the N-terminal domain of one variant, MITat 1.2, has been determined. The structure was solved using data collected from two crystal forms. Initially a partial model was built into an electron density map based on multiple isomorphous replacement phases and improved by phase combination methods. Subsequently this model was used to obtain the molecular replacement solution for a second crystal form, providing starting phases which were refined using 2-fold non-crystallographic symmetry averaging. The current model includes 362 residues and has been refined using X-PLOR to an R value of 0.22 for data between 7 and 2.9 A. The molecule is a dimer, approximately 100 A long, having an asymmetrical cross section with maximum dimensions of approximately 40 A x 60 A. Two long, approximately 70 A, alpha-helices from each monomer pack together to form, with several other helices, a core helix bundle that extends nearly the full length of the molecule. The "top" of the protein, which in the surface coat may be exposed to the external environment, is formed from the ends of the two long helices, a short three-stranded beta-sheet, and a strand having irregular conformation that packs above these secondary structure elements. Two conserved disulfide bridges are in this part of the molecule. Several elements of the MITat 1.2 sequence, which contribute to the formation of the helix bundle structure, have been identified. These elements can be found in the sequences of several different VSGs, suggesting that to some extent the VSG structure is conserved in those variants.


    Related Citations: 
    • Two Variant Surface Gylcoproteins of Trypanosoma Brucei of Different Sequence Classes Have Similar 6 Angstroms Resolution X-Ray Structures
      Metcalf, P.,Blum, M.,Freymann, D.,Turner, M.,Wiley, D.C.
      (1987) Nature 325: 84
    • 6 Angstroms-Resolution X-Ray Structure of a Variable Surface Glycoprotein from Trypanosoma Brucei
      Freymann, D.M.,Metcalf, P.,Turner, M.,Wiley, D.C.
      (1984) Nature 311: 167


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
VARIANT SURFACE GLYCOPROTEIN MITAT 1.2
A, B
364Trypanosoma brucei bruceiMutation(s): 0 
Find proteins for P26332 (Trypanosoma brucei brucei)
Go to UniProtKB:  P26332
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MAN
Query on MAN

Download SDF File 
Download CCD File 
B
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
BMA
Query on BMA

Download SDF File 
Download CCD File 
A
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A, B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Work: 0.220 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 95.500α = 90.00
b = 97.500β = 90.00
c = 123.700γ = 90.00
Software Package:
Software NamePurpose
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1992-01-15
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance