1GNZ

LECTIN I-B4 FROM GRIFFONIA SIMPLICIFOLIA (GS I-B4)METAL FREE FORM


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.228 
  • R-Value Observed: 0.228 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Isolectins I-A and I-B of Griffonia (Bandeiraea) Simplicifolia. Crystal Structure of Metal-Free Gs I-B(4) and Molecular Basis for Metal Binding and Monosaccharide Specificity.

Lescar, J.Loris, R.Mitchell, E.Gautier, C.Chazalet, V.Cox, V.Wyns, L.Perez, S.Breton, C.Imberty, A.

(2002) J Biol Chem 277: 6608

  • DOI: 10.1074/jbc.M109867200
  • Primary Citation of Related Structures:  
    1GNZ

  • PubMed Abstract: 
  • Seeds from the African legume shrub Griffonia simplicifolia contain several lectins. Among them the tetrameric lectin GS I-B(4) has strict specificity for terminal alpha Gal residues, whereas the closely related lectin GS I-A(4) can also bind to alpha GalNAc ...

    Seeds from the African legume shrub Griffonia simplicifolia contain several lectins. Among them the tetrameric lectin GS I-B(4) has strict specificity for terminal alpha Gal residues, whereas the closely related lectin GS I-A(4) can also bind to alpha GalNAc. These two lectins are commonly used as markers in histology or for research in xenotransplantation. To elucidate the basis for the fine difference in specificity, the amino acid sequences of both lectins have been determined and show 89% identity. The crystal structure of GS I-B(4), determined at 2.5-A resolution, reveals a new quaternary structure that has never been observed in other legume lectins. An unexpected loss of both Ca(2+) and Mn(2+) ions, which are necessary for carbohydrate binding in legume lectins, may be related to a particular amino acid sequence Pro-Glu-Pro in the metal binding loop. Comparison with demetallized concanavalin A reveals a different process for the loss of metal ions and for the subsequent loss of carbohydrate binding activity. The GS I-A x alpha GalNAc and GS I-B x alpha Gal complexes were constructed using homology modeling and docking approaches. The unusual presence of an aromatic amino acid at position 47 (Tyr in I-A and Trp in I-B) explains the strong preference for alpha-anomeric sugars in both isolectins. Alteration at one amino acid position, Ala(106) in I-A versus Glu(106) in I-B, is the basis for the observed specificities toward alpha GalNAc and alpha Gal.


    Organizational Affiliation

    Centre de Recherches sur les Macromolécules Végétales, CNRS, Université Joseph Fourier, BP 53, F-38041 Grenoble cedex 09, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
GSI-B4 ISOLECTINA257Griffonia simplicifoliaMutation(s): 0 
UniProt
Find proteins for Q8W1R6 (Griffonia simplicifolia)
Explore Q8W1R6 
Go to UniProtKB:  Q8W1R6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8W1R6
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download Ideal Coordinates CCD File 
D [auth A],
E [auth A]
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
PO4
Query on PO4

Download Ideal Coordinates CCD File 
B [auth A],
C [auth A]
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.228 
  • R-Value Observed: 0.228 
  • Space Group: P 64 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 75.927α = 90
b = 75.927β = 90
c = 190.566γ = 120
Software Package:
Software NamePurpose
CNSrefinement
HKLdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-11-29
    Type: Initial release
  • Version 1.1: 2011-09-07
    Changes: Atomic model, Data collection, Database references, Derived calculations, Non-polymer description, Other, Refinement description, Structure summary, Version format compliance
  • Version 1.2: 2019-12-18
    Changes: Derived calculations, Other
  • Version 1.3: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary