4ape: Difference between revisions

Revision as of 20:12, 21 February 2008

THE ACTIVE SITE OF ASPARTIC PROTEINASES

OverviewOverview

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 StructureAbout this Structure

4APE is a Single protein structure of sequence from Cryphonectria parasitica. This structure supersedes the now removed PDB entries 2APE and 1APE. The following page contains interesting information on the relation of 4APE with [Pepsin]. Active as Endothiapepsin, with EC number 3.4.23.22 Full crystallographic information is available from OCA.

ReferenceReference

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 Thu Feb 21 19:12:43 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 4: / Line 4: @@
 ==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.
+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==
-APE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cryphonectria_parasitica Cryphonectria parasitica]. This structure superseeds the now removed PDB entries 2APE and 1APE. The following page contains interesting information on the relation of 4APE with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb12_1.html Pepsin]]. Active as [http://en.wikipedia.org/wiki/Endothiapepsin Endothiapepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.22 3.4.23.22] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4APE OCA].
+APE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cryphonectria_parasitica Cryphonectria parasitica]. This structure supersedes the now removed PDB entries 2APE and 1APE. The following page contains interesting information on the relation of 4APE with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb12_1.html Pepsin]]. Active as [http://en.wikipedia.org/wiki/Endothiapepsin Endothiapepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.22 3.4.23.22] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4APE OCA].
 ==Reference==
@@ Line 15: / Line 15: @@
 [[Category: Pepsin]]
 [[Category: Single protein]]
-[[Category: Blundell, T.L.]]
+[[Category: Blundell, T L.]]
-[[Category: Cooper, J.B.]]
+[[Category: Cooper, J B.]]
-[[Category: Jenkins, J.A.]]
+[[Category: Jenkins, J A.]]
-[[Category: Pearl, L.H.]]
+[[Category: Pearl, L H.]]
-[[Category: Sewell, B.T.]]
+[[Category: Sewell, B T.]]
 [[Category: hydrolase (acid proteinase)]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 17:44:44 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:12:43 2008''