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3er3
From Proteopedia
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[[Image:3er3.jpg|left|200px]] | [[Image:3er3.jpg|left|200px]] | ||
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'''THE ACTIVE SITE OF ASPARTIC PROTEINASES''' | '''THE ACTIVE SITE OF ASPARTIC PROTEINASES''' | ||
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==About this Structure== | ==About this Structure== | ||
| - | 3ER3 is a [[Single protein]] structure | + | 3ER3 is a [[Single protein]] structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3ER3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Hoover, D.]] | [[Category: Hoover, D.]] | ||
[[Category: Veerapandian, B.]] | [[Category: Veerapandian, B.]] | ||
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 22:00:49 2008'' | |
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| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 19:00, 4 May 2008
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
3ER3 is a Single protein structure. 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 Page seeded by OCA on Sun May 4 22:00:49 2008
