2E7Q

Crystal structure of basic winged bean lectin in complex with b blood group trisaccharide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.198 

wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Generation of blood group specificity: New insights from structural studies on the complexes of A- and B-reactive saccharides with basic winged bean agglutinin

Kulkarni, K.A.Katiyar, S.Surolia, A.Vijayan, M.Suguna, K.

(2007) Proteins 68: 762-769

  • DOI: https://doi.org/10.1002/prot.21428
  • Primary Citation of Related Structures:  
    2E51, 2E53, 2E7Q, 2E7T

  • PubMed Abstract: 

    Basic winged bean agglutinin binds A-blood group substance with higher affinity and B-blood group substance with lesser affinity. It does not bind the O substance. The crystal structures of the lectin, complexed with A-reactive and B-reactive di and tri saccharides, have been determined. In addition, the complexes of the lectin with fucosylated A-trisaccharides and B-trisaccharides and with a variant of the A-trisaccharide have been modeled. These structures and models provide valuable insights into the structural basis of blood group specificities. All the four carbohydrate binding loops of the lectin contribute to the primary combining site while the loop of variable length contributes to the secondary binding site. In a significant advance to the current understanding, the interactions at the secondary binding site also contribute substantially, albeit in a subtle manner, to determine the blood group specificity. Compared with the interactions of the B-trisaccharide with the lectin, the third sugar residue of the A-reactive trisacharide forms an additional hydrogen bond with a lysine residue in the variable loop. In the former, the formation of such a hydrogen bond is prevented by a shift in the orientation of third sugar resulting from an internal hydrogen bond in it. The formation of this bond is also facilitated by an interaction dependent change in the rotamer conformation of the lysyl residue of the variable loop. Thus, the difference in the interactions at the secondary site is generated by coordinated movements in the ligand as well as the protein. A comparison of the crystal structure and the model of the complex involving the variant of the A-trisaccharide results in the delineation of the relative contributions of the interactions at the primary and the secondary sites in determining blood group specificity.


  • Organizational Affiliation

    Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Basic agglutinin
A, B, C, D
237Psophocarpus tetragonolobusMutation(s): 0 
UniProt
Find proteins for O24313 (Psophocarpus tetragonolobus)
Explore O24313 
Go to UniProtKB:  O24313
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO24313
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-L-fucopyranose-(1-3)-[2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)]2-acetamido-2-deoxy-beta-D-glucopyranose
E, F, H, K, N
E, F, H, K, N, O
3N-Glycosylation
Glycosylation Resources
GlyTouCan:  G11971MR
GlyCosmos:  G11971MR
GlyGen:  G11971MR
Entity ID: 3
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-galactopyranose-(1-3)-beta-D-galactopyranose-(1-4)-alpha-D-glucopyranose
G, J, M
3N/A
Glycosylation Resources
GlyTouCan:  G57666OY
GlyCosmos:  G57666OY
GlyGen:  G57666OY
Entity ID: 4
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-L-fucopyranose-(1-3)-[2-acetamido-2-deoxy-alpha-D-glucopyranose-(1-4)]2-acetamido-2-deoxy-beta-D-glucopyranose
I
3N-Glycosylation
Glycosylation Resources
GlyTouCan:  G91813SF
GlyCosmos:  G91813SF
GlyGen:  G91813SF
Entity ID: 5
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
L
2N-Glycosylation
Glycosylation Resources
GlyTouCan:  G42666HT
GlyCosmos:  G42666HT
GlyGen:  G42666HT
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.198 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 157.41α = 90
b = 90.545β = 90
c = 73.324γ = 90
Software Package:
Software NamePurpose
CNSrefinement
MAR345dtbdata collection
DENZOdata reduction
SCALEPACKdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-06-19
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2023-10-25
    Changes: Data collection, Database references, Refinement description, Structure summary