1er8
From Proteopedia
(New page: 200px<br /><applet load="1er8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1er8, resolution 2.0Å" /> '''THE ACTIVE SITE OF AS...) |
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| - | [[Image:1er8.gif|left|200px]]<br /><applet load="1er8" size=" | + | [[Image:1er8.gif|left|200px]]<br /><applet load="1er8" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1er8, resolution 2.0Å" /> | caption="1er8, resolution 2.0Å" /> | ||
'''THE ACTIVE SITE OF ASPARTIC PROTEINASES'''<br /> | '''THE ACTIVE SITE OF ASPARTIC PROTEINASES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The active site of the aspartic proteinase, endothiapepsin, has been | + | The active site of the aspartic proteinase, endothiapepsin, has been defined by X-ray analysis and restrained least-squares refinement at 2.1 A resolution with a crystallographic agreement value of 0.16. The environments of the two catalytically important aspartyl groups are remarkably similar and the contributions of the NH2- and COOH-terminal domains to the catalytic centre are related by a local 2-fold axis. The carboxylates of the aspartyls share a hydrogen bond and have equivalent contacts to a bound water molecule or hydroxonium ion lying on the local diad. The main chains around 32 and 215 are connected by a novel interaction involving diad-related threonines. It is suggested that the two pKa values of the active site aspartyls arise from a structure not unlike that in maleic acid with a hydrogen-bonded intermediate species and a dicarboxylate characterised by electrostatic repulsions between the two negatively charged groups. |
==About this Structure== | ==About this Structure== | ||
| - | 1ER8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Active as [http://en.wikipedia.org/wiki/Hydrolase Hydrolase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.103, 3.4.23.18, 3.4.23.28 and 3.4.23.30 3.4.21.103, 3.4.23.18, 3.4.23.28 and 3.4.23.30] Full crystallographic information is available from [http:// | + | 1ER8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Active as [http://en.wikipedia.org/wiki/Hydrolase Hydrolase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.103, 3.4.23.18, 3.4.23.28 and 3.4.23.30 3.4.21.103, 3.4.23.18, 3.4.23.28 and 3.4.23.30] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ER8 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Hydrolase]] | [[Category: Hydrolase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Blundell, T | + | [[Category: Blundell, T L.]] |
| - | [[Category: Cooper, J | + | [[Category: Cooper, J B.]] |
| - | [[Category: Hemmings, A | + | [[Category: Hemmings, A M.]] |
[[Category: Szelke, M.]] | [[Category: Szelke, M.]] | ||
[[Category: Veerapandian, B.]] | [[Category: Veerapandian, B.]] | ||
[[Category: hydrolase (acid proteinase)]] | [[Category: hydrolase (acid proteinase)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:30:38 2008'' |
Revision as of 10:30, 21 February 2008
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THE ACTIVE SITE OF ASPARTIC PROTEINASES
Overview
The active site of the aspartic proteinase, endothiapepsin, has been defined by X-ray analysis and restrained least-squares refinement at 2.1 A resolution with a crystallographic agreement value of 0.16. The environments of the two catalytically important aspartyl groups are remarkably similar and the contributions of the NH2- and COOH-terminal domains to the catalytic centre are related by a local 2-fold axis. The carboxylates of the aspartyls share a hydrogen bond and have equivalent contacts to a bound water molecule or hydroxonium ion lying on the local diad. The main chains around 32 and 215 are connected by a novel interaction involving diad-related threonines. It is suggested that the two pKa values of the active site aspartyls arise from a structure not unlike that in maleic acid with a hydrogen-bonded intermediate species and a dicarboxylate characterised by electrostatic repulsions between the two negatively charged groups.
About this Structure
1ER8 is a Single protein structure of sequence from [1]. Active as Hydrolase, with EC number 3.4.23.18, 3.4.23.28 and 3.4.23.30 3.4.21.103, 3.4.23.18, 3.4.23.28 and 3.4.23.30 Full crystallographic information is available from OCA.
Reference
The active site of aspartic proteinases., Pearl L, Blundell T, FEBS Lett. 1984 Aug 20;174(1):96-101. PMID:6381096
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