2EAK

Crystal structure of human galectin-9 N-terminal CRD in complex with lactose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.97 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.223 
  • R-Value Observed: 0.226 

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Ligand Structure Quality Assessment 


This is version 2.0 of the entry. See complete history


Literature

Structural analysis of the human galectin-9 N-terminal carbohydrate recognition domain reveals unexpected properties that differ from the mouse orthologue.

Nagae, M.Nishi, N.Nakamura-Tsuruta, S.Hirabayashi, J.Wakatsuki, S.Kato, R.

(2008) J Mol Biol 375: 119-135

  • DOI: https://doi.org/10.1016/j.jmb.2007.09.060
  • Primary Citation of Related Structures:  
    2EAK, 2EAL

  • PubMed Abstract: 

    Galectins are a family of beta-galactoside-binding lectins that contain a conserved carbohydrate recognition domain (CRD). They exhibit high affinities for small beta-galactosides as well as variable binding specificities for complex glycoconjugates. Structural and biochemical analyses of the mechanism governing specific carbohydrate recognition provide a useful template to elucidate the function of these proteins. Here we report the crystal structures of the human galectin-9 N-terminal CRD (NCRD) in the presence of lactose and Forssman pentasaccharide. Mouse galectin-9 NCRD, the structure of which was previously solved by our group, forms a non-canonical dimer in both the crystal state and in solution. Human galectin-9 NCRD, however, exists as a monomer in crystals, despite a high sequence identity to the mouse homologue. Comparative frontal affinity chromatography analysis of the mouse and human galectin-9 NCRDs revealed different carbohydrate binding specificities, with disparate affinities for complex glycoconjugates. Human galectin-9 NCRD exhibited a high affinity for Forssman pentasaccharide; the association constant for mouse galectin-9 NCRD was 100-fold less than that observed for the human protein. The combination of structural data with mutational studies demonstrated that non-conserved amino acid residues on the concave surface were important for determination of target specificities. The human galectin-9 NCRD exhibited greater inhibition of cell proliferation than the mouse NCRD. We discuss the biochemical and structural differences between highly homologous proteins from different species.


  • Organizational Affiliation

    Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Galectin-9
A, B, C
148Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for O00182 (Homo sapiens)
Explore O00182 
Go to UniProtKB:  O00182
PHAROS:  O00182
GTEx:  ENSG00000168961 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO00182
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
beta-D-galactopyranose-(1-4)-alpha-D-glucopyranose
D, E
2N/A
Glycosylation Resources
GlyTouCan:  G88362QR
GlyCosmos:  G88362QR
GlyGen:  G88362QR
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
DTV
Query on DTV

Download Ideal Coordinates CCD File 
F [auth A](2S,3S)-1,4-DIMERCAPTOBUTANE-2,3-DIOL
C4 H10 O2 S2
VHJLVAABSRFDPM-QWWZWVQMSA-N
GOL
Query on GOL

Download Ideal Coordinates CCD File 
G [auth B]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.97 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.223 
  • R-Value Observed: 0.226 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 70.681α = 90
b = 118.687β = 90
c = 132.052γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-09-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.2: 2012-02-22
    Changes: Database references, Non-polymer description
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Non-polymer description, Structure summary