1k2i
From Proteopedia
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|PDB= 1k2i |SIZE=350|CAPTION= <scene name='initialview01'>1k2i</scene>, resolution 1.8Å | |PDB= 1k2i |SIZE=350|CAPTION= <scene name='initialview01'>1k2i</scene>, resolution 1.8Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=SN1:2,4-DIHYDROXY-TRANS+CINNAMIC+ACID'>SN1</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Chymotrypsin Chymotrypsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.1 3.4.21.1] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Chymotrypsin Chymotrypsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.1 3.4.21.1] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1gct|1GCT]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1k2i FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1k2i OCA], [http://www.ebi.ac.uk/pdbsum/1k2i PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1k2i RCSB]</span> | ||
}} | }} | ||
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[[Category: Ng, K K.S.]] | [[Category: Ng, K K.S.]] | ||
[[Category: Ullah, N.]] | [[Category: Ullah, N.]] | ||
| - | [[Category: SN1]] | ||
| - | [[Category: SO4]] | ||
[[Category: enzyme-inhibitor complex]] | [[Category: enzyme-inhibitor complex]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:42:26 2008'' |
Revision as of 18:42, 30 March 2008
| |||||||
| , resolution 1.8Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Activity: | Chymotrypsin, with EC number 3.4.21.1 | ||||||
| Related: | 1GCT
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of Gamma-Chymotrypsin in Complex with 7-Hydroxycoumarin
Overview
The 1.8 A crystal structure of 7-hydroxycoumarin (7-HC) bound to chymotrypsin reveals that this inhibitor forms a planar cinnamate acyl-enzyme complex. The phenyl ring of the bound inhibitor forms numerous van der Waals contacts in the S1 pocket of the enzyme, with the p-hydroxyl group donating a hydrogen bond to the main-chain oxygen atom of Ser217, and the o-hydroxyl group forming a water-mediated hydrogen bond with the carbonyl oxygen of Val227. The structure of the acyl-enzyme complex suggests that the mechanism of inhibition of 7-HC involves nucleophilic attack by the Ser195 O(gamma) atom on the carbonyl carbon atom of the inhibitor, accompanied by the breaking of the 2-pyrone ring of the inhibitor, and leading to the formation of a cinnamate acyl-enzyme derivative via a tetrahedral transition state. Comparisons with structures of photoreversible cinnamates bound to chymotrypsin reveal that although 7-HC interacts with the enzyme in a similar fashion, the binding of 7-HC to chymotrypsin takes place in a productive conformation in contrast to the photoreversible cinnamates. In summary, the 7-HC-chymotrypsin complex provides basic insight into the inhibition of chymotrypsin by natural coumarins and provides a structural basis for the design of more potent mechanism-based inhibitors against a wide range of biologically important chymotrypsin-like enzymes.
About this Structure
1K2I is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.
Reference
Crystal structure of gamma-chymotrypsin in complex with 7-hydroxycoumarin., Ghani U, Ng KK, Atta-ur-Rahman, Choudhary MI, Ullah N, James MN, J Mol Biol. 2001 Nov 30;314(3):519-25. PMID:11846564
Page seeded by OCA on Sun Mar 30 21:42:26 2008
