1u67
From Proteopedia
(New page: 200px<br /><applet load="1u67" size="450" color="white" frame="true" align="right" spinBox="true" caption="1u67, resolution 3.1Å" /> '''Crystal Structure of ...) |
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| - | [[Image:1u67.jpg|left|200px]]<br /><applet load="1u67" size=" | + | [[Image:1u67.jpg|left|200px]]<br /><applet load="1u67" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1u67, resolution 3.1Å" /> | caption="1u67, resolution 3.1Å" /> | ||
'''Crystal Structure of Arachidonic Acid Bound to a Mutant of Prostagladin H Synthase-1 that Forms Predominantly 11-HPETE.'''<br /> | '''Crystal Structure of Arachidonic Acid Bound to a Mutant of Prostagladin H Synthase-1 that Forms Predominantly 11-HPETE.'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Kinetic studies and analysis of the products formed by native and mutant | + | Kinetic studies and analysis of the products formed by native and mutant forms of ovine prostaglandin endoperoxide H synthase-1 (oPGHS-1) have suggested that arachidonic acid (AA) can exist in the cyclooxygenase active site of the enzyme in three different, catalytically competent conformations that lead to prostaglandin G2 (PGG2), 11R-hydroperoxyeicosatetraenoic acid (HPETE), and 15R,S-HPETE, respectively. We have identified an oPGHS-1 mutant (V349A/W387F) that forms predominantly 11R-HPETE. Thus, the preferred catalytically competent arrangement of AA in the cyclooxygenase site of this double mutant must be one that leads to 11-HPETE. The crystal structure of Co3+-protoporphyrin IX V349A/W387F oPGHS-1 in a complex with AA was determined to 3.1 A. Significant differences are observed in the positions of atoms C-3, C-4, C-5, C-6, C-10, C-11, and C-12 of bound AA between native and V349A/W387F oPGHS-1; in comparison, the positions of the side chains of cyclooxygenase active site residues are unchanged. The structure of the double mutant presented here provides structural insight as to how Val349 and Trp387 help position C-9 and C-11 of AA so that the incipient 11-peroxyl radical intermediate is able to add to C-9 to form the 9,11 endoperoxide group of PGG2. In the V349A/W387F oPGHS-1.AA complex the locations of C-9 and C-11 of AA with respect to one another make it difficult to form the endoperoxide group from the 11-hydroperoxyl radical. Therefore, the reaction apparently aborts yielding 11R-HPETE instead of PGG2. In addition, the observed differences in the positions of carbon atoms of AA bound to this mutant provides indirect support for the concept that the conformer of AA shown previously to be bound within the cyclooxygenase active site of native oPGHS-1 is the one that leads to PGG2. |
==About this Structure== | ==About this Structure== | ||
| - | 1U67 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Ovis_aries Ovis aries] with BOG, COH and ACD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Prostaglandin-endoperoxide_synthase Prostaglandin-endoperoxide synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.99.1 1.14.99.1] Full crystallographic information is available from [http:// | + | 1U67 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Ovis_aries Ovis aries] with <scene name='pdbligand=BOG:'>BOG</scene>, <scene name='pdbligand=COH:'>COH</scene> and <scene name='pdbligand=ACD:'>ACD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Prostaglandin-endoperoxide_synthase Prostaglandin-endoperoxide synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.99.1 1.14.99.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1U67 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Prostaglandin-endoperoxide synthase]] | [[Category: Prostaglandin-endoperoxide synthase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Garavito, R | + | [[Category: Garavito, R M.]] |
| - | [[Category: Harman, C | + | [[Category: Harman, C A.]] |
| - | [[Category: Rieke, C | + | [[Category: Rieke, C J.]] |
| - | [[Category: Smith, W | + | [[Category: Smith, W L.]] |
[[Category: ACD]] | [[Category: ACD]] | ||
[[Category: BOG]] | [[Category: BOG]] | ||
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[[Category: heme]] | [[Category: heme]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:20:58 2008'' |
Revision as of 13:20, 21 February 2008
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Crystal Structure of Arachidonic Acid Bound to a Mutant of Prostagladin H Synthase-1 that Forms Predominantly 11-HPETE.
Overview
Kinetic studies and analysis of the products formed by native and mutant forms of ovine prostaglandin endoperoxide H synthase-1 (oPGHS-1) have suggested that arachidonic acid (AA) can exist in the cyclooxygenase active site of the enzyme in three different, catalytically competent conformations that lead to prostaglandin G2 (PGG2), 11R-hydroperoxyeicosatetraenoic acid (HPETE), and 15R,S-HPETE, respectively. We have identified an oPGHS-1 mutant (V349A/W387F) that forms predominantly 11R-HPETE. Thus, the preferred catalytically competent arrangement of AA in the cyclooxygenase site of this double mutant must be one that leads to 11-HPETE. The crystal structure of Co3+-protoporphyrin IX V349A/W387F oPGHS-1 in a complex with AA was determined to 3.1 A. Significant differences are observed in the positions of atoms C-3, C-4, C-5, C-6, C-10, C-11, and C-12 of bound AA between native and V349A/W387F oPGHS-1; in comparison, the positions of the side chains of cyclooxygenase active site residues are unchanged. The structure of the double mutant presented here provides structural insight as to how Val349 and Trp387 help position C-9 and C-11 of AA so that the incipient 11-peroxyl radical intermediate is able to add to C-9 to form the 9,11 endoperoxide group of PGG2. In the V349A/W387F oPGHS-1.AA complex the locations of C-9 and C-11 of AA with respect to one another make it difficult to form the endoperoxide group from the 11-hydroperoxyl radical. Therefore, the reaction apparently aborts yielding 11R-HPETE instead of PGG2. In addition, the observed differences in the positions of carbon atoms of AA bound to this mutant provides indirect support for the concept that the conformer of AA shown previously to be bound within the cyclooxygenase active site of native oPGHS-1 is the one that leads to PGG2.
About this Structure
1U67 is a Single protein structure of sequence from Ovis aries with , and as ligands. Active as Prostaglandin-endoperoxide synthase, with EC number 1.14.99.1 Full crystallographic information is available from OCA.
Reference
Crystal structure of arachidonic acid bound to a mutant of prostaglandin endoperoxide H synthase-1 that forms predominantly 11-hydroperoxyeicosatetraenoic acid., Harman CA, Rieke CJ, Garavito RM, Smith WL, J Biol Chem. 2004 Oct 8;279(41):42929-35. Epub 2004 Jul 30. PMID:15292194
Page seeded by OCA on Thu Feb 21 15:20:58 2008
Categories: Ovis aries | Prostaglandin-endoperoxide synthase | Single protein | Garavito, R M. | Harman, C A. | Rieke, C J. | Smith, W L. | ACD | BOG | COH | 11-hete | Arachidonic acid | Cox-1 | Cox-2 | Cyclooxgenase | Eicosanoid | Heme
