2CH9
Crystal structure of dimeric human cystatin F
Summary for 2CH9
| Entry DOI | 10.2210/pdb2ch9/pdb |
| Descriptor | CYSTATIN F, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[beta-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (6 entities in total) |
| Functional Keywords | inhibitor, cysteine protease inhibitor, glycoprotein |
| Biological source | HOMO SAPIENS (HUMAN) |
| Total number of polymer chains | 1 |
| Total formula weight | 16433.33 |
| Authors | Schuettelkopf, A.W.,van Aalten, D.M.F. (deposition date: 2006-03-13, release date: 2006-04-04, Last modification date: 2024-10-23) |
| Primary citation | Schuttelkopf, A.W.,Hamilton, G.,Watts, C.,Van Aalten, D.M.F. Structural Basis of Reduction-Dependent Activation of Human Cystatin F. J.Biol.Chem., 281:16570-, 2006 Cited by PubMed Abstract: Cystatins are important natural cysteine protease inhibitors targeting primarily papain-like cysteine proteases, including cathepsins and parasitic proteases like cruzipain, but also mammalian asparaginyl endopeptidase. Mammalian cystatin F, which is expressed almost exclusively in hematopoietic cells and accumulates in lysosome-like organelles, has been implicated in the regulation of antigen presentation and other immune processes. It is an unusual cystatin superfamily member with a redox-regulated activation mechanism and a restricted specificity profile. We describe the 2.1A crystal structure of human cystatin F in its dimeric "off" state. The two monomers interact in a fashion not seen before for cystatins or cystatin-like proteins that is crucially dependent on an unusual intermolecular disulfide bridge, suggesting how reduction leads to monomer formation and activation. Strikingly, core sugars for one of the two N-linked glycosylation sites of cystatin F are well ordered, and their conformation and interactions with the protein indicate that this unique feature of cystatin F may modulate its inhibitory properties, in particular its reduced affinity toward asparaginyl endopeptidase compared with other cystatins. PubMed: 16601115DOI: 10.1074/JBC.M601033200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.1 Å) |
Structure validation
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