1tn3
THE C-TYPE LECTIN CARBOHYDRATE RECOGNITION DOMAIN OF HUMAN TETRANECTINTHE C-TYPE LECTIN CARBOHYDRATE RECOGNITION DOMAIN OF HUMAN TETRANECTIN
Structural highlights
FunctionTETN_HUMAN Tetranectin binds to plasminogen and to isolated kringle 4. May be involved in the packaging of molecules destined for exocytosis. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTetranectin (TN) is a C-type lectin involved in fibrinolysis, being the only endogenous ligand known to bind specifically to the kringle 4 domain of plasminogen. TN was originally isolated from plasma, but shows a wide tissue distribution. Furthermore, TN has been found in the extracellular matrix of certain human carcinomas, whereas none or little is present in the corresponding normal tissue. The crystal structure of full-length trimeric TN (2.8 A resolution) has recently been published [Nielsen et al. (1997). FEBS Lett. 412, 388-396]. The crystal structure of the carbohydrate recognition domain (CRD) of human TN (TN3) has been determined separately at 2.0 A resolution in order to obtain detailed information on the two calcium binding sites. This information is essential for the elucidation of the specificity of TN towards oligosaccharides. TN3 crystallizes as a dimer, whereas it appears as a monomer in solution. The overall fold of TN3 is similar to other known CRDs. Each monomer is built of two distinct regions, one region consisting of six beta-strands and two alpha-helices, and the other region is composed of four loops harboring two calcium ions. The calcium ion at site 1 forms an eightfold coordinated complex and has Asp116, Glu120, Gly147, Glu150, Asn151, and one water molecule as ligands. The calcium ion at site 2, which is believed to be involved in recognition and binding of oligosaccharides, is sevenfold coordinated with ligands Gln143, Asp145, Glu150, Asp165, and two water molecules. One sulfate ion has been located at the surface of TN3, forming contacts to Glu120, Lys148, Asn106 of a symmetry-related molecule, and to an ethanol molecule. Structure of the C-type lectin carbohydrate recognition domain of human tetranectin.,Kastrup JS, Nielsen BB, Rasmussen H, Holtet TL, Graversen JH, Etzerodt M, Thogersen HC, Larsen IK Acta Crystallogr D Biol Crystallogr. 1998 Sep 1;54(Pt 5):757-66. PMID:9757090[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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