This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2ch9
From Proteopedia
| Line 4: | Line 4: | ||
==Overview== | ==Overview== | ||
| - | Cystatins are important natural cysteine protease inhibitors targeting | + | 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. |
==About this Structure== | ==About this Structure== | ||
| Line 13: | Line 13: | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Aalten, D | + | [[Category: Aalten, D M.F Van.]] |
| - | [[Category: Schuettelkopf, A | + | [[Category: Schuettelkopf, A W.]] |
[[Category: ACT]] | [[Category: ACT]] | ||
[[Category: NAG]] | [[Category: NAG]] | ||
| Line 24: | Line 24: | ||
[[Category: thiol protease inhibitor]] | [[Category: thiol protease inhibitor]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:48:35 2008'' |
Revision as of 14:48, 21 February 2008
|
CRYSTAL STRUCTURE OF DIMERIC HUMAN CYSTATIN F
Overview
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.
About this Structure
2CH9 is a Single protein structure of sequence from Homo sapiens with , and as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Structural basis of reduction-dependent activation of human cystatin F., Schuttelkopf AW, Hamilton G, Watts C, van Aalten DM, J Biol Chem. 2006 Jun 16;281(24):16570-5. Epub 2006 Apr 6. PMID:16601115
Page seeded by OCA on Thu Feb 21 16:48:35 2008
