1k2i
From Proteopedia
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| - | [[Image:1k2i.jpg|left|200px]] | + | [[Image:1k2i.jpg|left|200px]] |
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| - | '''Crystal Structure of Gamma-Chymotrypsin in Complex with 7-Hydroxycoumarin''' | + | {{Structure |
| + | |PDB= 1k2i |SIZE=350|CAPTION= <scene name='initialview01'>1k2i</scene>, resolution 1.8Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> and <scene name='pdbligand=SN1:2,4-DIHYDROXY-TRANS CINNAMIC ACID'>SN1</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] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''Crystal Structure of Gamma-Chymotrypsin in Complex with 7-Hydroxycoumarin''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1K2I is a [ | + | 1K2I is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K2I OCA]. |
==Reference== | ==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:[http:// | + | 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:[http://www.ncbi.nlm.nih.gov/pubmed/11846564 11846564] |
[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Chymotrypsin]] | [[Category: Chymotrypsin]] | ||
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[[Category: enzyme-inhibitor complex]] | [[Category: enzyme-inhibitor complex]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 12:11:41 2008'' |
Revision as of 10:11, 20 March 2008
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| , resolution 1.8Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Activity: | Chymotrypsin, with EC number 3.4.21.1 | ||||||
| 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
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