1HJX

Ligand-induced signalling and conformational change of the 39 kD glycoprotein from human articular chondrocytes

Summary for 1HJX

• Entry DOI: 10.2210/pdb1hjx/pdb
• Related: 1HJV 1HJW 1LA7
• Descriptor: CHITINASE-3 LIKE PROTEIN 1, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, SULFATE ION, ... (5 entities in total)
• Functional Keywords: lectin, chi-lectin, chitinase, arthristis, chondrocytes, sugar binding protein
• Biological source: HOMO SAPIENS (HUMAN)
• Total number of polymer chains: 4
• Total formula weight: 166086.64

Authors

Houston, D.R.,Recklies, A.D.,Krupa, J.C.,Van Aalten, D.M.F. (deposition date: 2003-02-28, release date: 2003-03-11, Last modification date: 2024-10-23)

Primary citation

Houston, D.R.,Recklies, A.D.,Krupa, J.C.,Van Aalten, D.M.F.
Structure and Ligand-Induced Conformational Change of the 39-kDa Glycoprotein from Human Articular Chondrocytes
J.Biol.Chem., 278:30206-, 2003

PubMed Abstract: The 39-kDa human cartilage glycoprotein (HCGP39), a member of a novel family of chitinase-like lectins (Chilectins), is overexpressed in articular chondrocytes and certain cancers. Proposed functions of this protein include a role in connective tissue remodeling and defense against pathogens. Similar to other Chi-lectins, HCGP39 promotes the growth of connective tissue cells. The ability of HCGP39 to activate cytoplasmic signaling pathways suggests the presence of a ligand for this protein at the cell surface. There is currently no information regarding the identity of any physiological or pathological ligands of the Chi-lectins or the nature of the protein-ligand interaction. Here, we show that HCGP39 is able to bind chitooligosaccharides with micromolar affinity. Crystal structures of the native protein and a complex with GlcNAc8 show that the ligand is bound in identical fashion to family 18 chitinases. However, unlike the chitinases, binding of the oligosaccharide ligand to HCGP39 induces a large conformational change. Thus, HCGP39 could be a lectin that binds chitin-like oligosaccharide ligands and possibly plays a role in innate responses to chitinous pathogens, such as fungi and nematodes.

PubMed: 12775711
DOI: 10.1074/JBC.M303371200

Experimental method

X-RAY DIFFRACTION (1.85 Å)