3N3H

Erythrina corallodendron lectin mutant (Y106G) in complex with citrate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.184 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Literature

Modification of the sugar specificity of a plant lectin: structural studies on a point mutant of Erythrina corallodendron lectin.

Thamotharan, S.Karthikeyan, T.Kulkarni, K.A.Shetty, K.N.Surolia, A.Vijayan, M.Suguna, K.

(2011) Acta Crystallogr D Biol Crystallogr 67: 218-227

  • DOI: https://doi.org/10.1107/S0907444911004525
  • Primary Citation of Related Structures:  
    3N35, 3N36, 3N3H

  • PubMed Abstract: 

    A mutant of Erythrina corallodendron lectin was generated with the aim of enhancing its affinity for N-acetylgalactosamine. A tyrosine residue close to the binding site of the lectin was mutated to a glycine in order to facilitate stronger interactions between the acetamido group of the sugar and the lectin which were prevented by the side chain of the tyrosine in the wild-type lectin. The crystal structures of this Y106G mutant lectin in complex with galactose and N-acetylgalactosamine have been determined. A structural rationale has been provided for the differences in the relative binding affinities of the wild-type and mutant lectins towards the two sugars based on the structures. A hydrogen bond between the O6 atom of the sugars and the variable loop of the carbohydrate-binding site of the lectin is lost in the mutant complexes owing to a conformational change in the loop. This loss is compensated by an additional hydrogen bond that is formed between the acetamido group of the sugar and the mutant lectin in the complex with N-acetylgalactosamine, resulting in a higher affinity of the mutant lectin for N-acetylgalactosamine compared with that for galactose, in contrast to the almost equal affinity of the wild-type lectin for the two sugars. The structure of a complex of the mutant with a citrate ion bound at the carbohydrate-binding site that was obtained while attempting to crystallize the complexes with sugars is also presented.


  • 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
Lectin242Erythrina corallodendronMutation(s): 1 
UniProt
Find proteins for P16404 (Erythrina corallodendron)
Explore P16404 
Go to UniProtKB:  P16404
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP16404
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.184 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 102.784α = 90
b = 102.784β = 90
c = 56.975γ = 120
Software Package:
Software NamePurpose
MAR345dtbdata collection
PHASERphasing
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-03-30
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2023-11-01
    Changes: Data collection, Database references, Derived calculations, Refinement description