1hax
From Proteopedia
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| - | [[Image:1hax.gif|left|200px]]<br /><applet load="1hax" size=" | + | [[Image:1hax.gif|left|200px]]<br /><applet load="1hax" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1hax, resolution 1.6Å" /> | caption="1hax, resolution 1.6Å" /> | ||
'''SNAPSHOTS OF SERINE PROTEASE CATALYSIS: (A) ACYL-ENZYME INTERMEDIATE BETWEEN PORCINE PANCREATIC ELASTASE AND HUMAN BETA-CASOMORPHIN-7 AT PH 5'''<br /> | '''SNAPSHOTS OF SERINE PROTEASE CATALYSIS: (A) ACYL-ENZYME INTERMEDIATE BETWEEN PORCINE PANCREATIC ELASTASE AND HUMAN BETA-CASOMORPHIN-7 AT PH 5'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1HAX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with CA and SO4 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Transferred_entry:_3.4.21.36 Transferred entry: 3.4.21.36], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.11 3.4.21.11] Known structural/functional Site: <scene name='pdbsite=CAT:Active Site Catalytic Triad'>CAT</scene>. Full crystallographic information is available from [http:// | + | 1HAX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Transferred_entry:_3.4.21.36 Transferred entry: 3.4.21.36], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.11 3.4.21.11] Known structural/functional Site: <scene name='pdbsite=CAT:Active+Site+Catalytic+Triad'>CAT</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HAX OCA]. |
==Reference== | ==Reference== | ||
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[[Category: serine proteinase]] | [[Category: serine proteinase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:48:15 2008'' |
Revision as of 07:48, 3 February 2008
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SNAPSHOTS OF SERINE PROTEASE CATALYSIS: (A) ACYL-ENZYME INTERMEDIATE BETWEEN PORCINE PANCREATIC ELASTASE AND HUMAN BETA-CASOMORPHIN-7 AT PH 5
Overview
Studies on the catalytic mechanism and inhibition of serine proteases are, widely used as paradigms for teaching enzyme catalysis. Ground-breaking, work on the structures of chymotrypsin and subtilisin led to the idea of a, conserved catalytic triad formed by the active site Ser, His and Asp, residues. An oxyanion hole, consisting of the peptide amide of the active, site serine and a neighbouring glycine, was identified, and hydrogen, bonding in the oxyanion hole was suggested to stabilize the two proposed, tetrahedral intermediates on the catalytic pathway. Here we show electron, density changes consistent with the formation of a tetrahedral, intermediate during the hydrolysis of an acyl-enzyme complex formed, between a natural heptapeptide and elastase. No electron density for an, enzyme-product complex was observed. The structures also suggest a, mechanism for the synchronization of hydrolysis and peptide release, triggered by the conversion of the sp2 hybridized carbonyl carbon to an, sp3 carbon in the tetrahedral intermediate. This affects the location of, the peptide in the active site cleft, triggering the collapse of a, hydrogen bonding network between the peptide and the beta-sheet of the, active site.
About this Structure
1HAX is a Single protein structure of sequence from Homo sapiens and Sus scrofa with and as ligands. Active as Transferred entry: 3.4.21.36, with EC number 3.4.21.11 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
X-ray snapshots of serine protease catalysis reveal a tetrahedral intermediate., Wilmouth RC, Edman K, Neutze R, Wright PA, Clifton IJ, Schneider TR, Schofield CJ, Hajdu J, Nat Struct Biol. 2001 Aug;8(8):689-94. PMID:11473259
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