1NWU

Crystal structure of human cartilage gp39 (HC-gp39) in complex with chitotetraose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.225 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure and carbohydrate-binding properties of the human cartilage glycoprotein-39

Fusetti, F.Pijning, T.Kalk, K.H.Bos, E.Dijkstra, B.W.

(2003) J.Biol.Chem. 278: 37753-37760

  • DOI: 10.1074/jbc.M303137200
  • Primary Citation of Related Structures:  1NWR, 1NWS, 1NWT

  • PubMed Abstract: 
  • The human cartilage glycoprotein-39 (HCgp-39 or YKL40) is expressed by synovial cells and macrophages during inflammation. Its precise physiological role is unknown. However, it has been proposed that HCgp-39 acts as an autoantigen in rheumatoid arth ...

    The human cartilage glycoprotein-39 (HCgp-39 or YKL40) is expressed by synovial cells and macrophages during inflammation. Its precise physiological role is unknown. However, it has been proposed that HCgp-39 acts as an autoantigen in rheumatoid arthritis, and high expression levels have been associated with cancer development. HCgp-39 shares high sequence homology with family 18 chitinases, and although it binds to chitin it lacks enzymatic activity. The crystal structure of HCgp-39 shows that the protein displays a (beta/alpha)8-barrel fold with an insertion of an alpha + beta domain. A 43-A long carbohydrate-binding cleft is present at the C-terminal side of the beta-strands in the (beta/alpha)8 barrel. Binding of chitin fragments of different lengths identified nine sugar-binding subsites in the groove. Protein-carbohydrate interactions are mainly mediated by stacking of side chains of aromatic amino acid residues. Surprisingly, the specificity of chitin binding to HCgp-39 depends on the length of the oligosaccharide. Although chitin disaccharides tend to occupy the distal subsites, longer chains bind preferably to the central subsites in the groove. Despite the absence of enzymatic activity, long chitin fragments are distorted upon binding, with the GlcNAc at subsite -1 in a boat conformation, similar to what has been observed in chitinases. The presence of chitin in the human body has never been documented so far. However, the binding features observed in the complex structures suggest that either chitin or a closely related oligosaccharide could act as the physiological ligand for HCgp-39.


    Organizational Affiliation

    Laboratory of Biophysical Chemistry, Department of Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Chitinase-3 like protein 1
A, B, C, D
362Homo sapiensGene Names: CHI3L1
Find proteins for P36222 (Homo sapiens)
Go to Gene View: CHI3L1
Go to UniProtKB:  P36222
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NDG
Query on NDG

Download SDF File 
Download CCD File 
A, B, C, D
2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE
C8 H15 N O6
OVRNDRQMDRJTHS-PVFLNQBWSA-N
 Ligand Interaction
NAG
Query on NAG

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.225 
  • Space Group: P 43
Unit Cell:
Length (Å)Angle (°)
a = 128.712α = 90.00
b = 128.712β = 90.00
c = 108.838γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSphasing
DENZOdata reduction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-08-26
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance