2fnq
From Proteopedia
(New page: 200px<br /><applet load="2fnq" size="450" color="white" frame="true" align="right" spinBox="true" caption="2fnq, resolution 3.200Å" /> '''Insights from the X...) |
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| - | [[Image:2fnq.gif|left|200px]]<br /><applet load="2fnq" size=" | + | [[Image:2fnq.gif|left|200px]]<br /><applet load="2fnq" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2fnq, resolution 3.200Å" /> | caption="2fnq, resolution 3.200Å" /> | ||
'''Insights from the X-ray crystal structure of coral 8R-lipoxygenase: calcium activation via A C2-like domain and a structural basis of product chirality'''<br /> | '''Insights from the X-ray crystal structure of coral 8R-lipoxygenase: calcium activation via A C2-like domain and a structural basis of product chirality'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Lipoxygenases (LOXs) catalyze the regio- and stereospecific dioxygenation | + | Lipoxygenases (LOXs) catalyze the regio- and stereospecific dioxygenation of polyunsaturated membrane-embedded fatty acids. We report here the 3.2 A resolution structure of 8R-LOX from the Caribbean sea whip coral Plexaura homomalla, a LOX isozyme with calcium dependence and the uncommon R chiral stereospecificity. Structural and spectroscopic analyses demonstrated calcium binding in a C2-like membrane-binding domain, illuminating the function of similar amino acids in calcium-activated mammalian 5-LOX, the key enzyme in the pathway to the pro-inflammatory leukotrienes. Mutation of Ca(2+)-ligating amino acids in 8R-LOX resulted not only in a diminished capacity to bind membranes, as monitored by fluorescence resonance energy transfer, but also in an associated loss of Ca(2+)-regulated enzyme activity. Moreover, a structural basis for R chiral specificity is also revealed; creation of a small oxygen pocket next to Gly(428) (Ala in all S-LOX isozymes) promoted C-8 oxygenation with R chirality on the activated fatty acid substrate. |
==About this Structure== | ==About this Structure== | ||
| - | 2FNQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Plexaura_homomalla Plexaura homomalla] with FE2 and CA as [http://en.wikipedia.org/wiki/ligands ligands]. This structure | + | 2FNQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Plexaura_homomalla Plexaura homomalla] with <scene name='pdbligand=FE2:'>FE2</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. This structure supersedes the now removed PDB entry 1ZQ4. Active as [http://en.wikipedia.org/wiki/Arachidonate_8-lipoxygenase Arachidonate 8-lipoxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.13.11.40 1.13.11.40] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FNQ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Plexaura homomalla]] | [[Category: Plexaura homomalla]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Brash, A | + | [[Category: Brash, A R.]] |
| - | [[Category: Newcomer, M | + | [[Category: Newcomer, M E.]] |
| - | [[Category: Oldham, M | + | [[Category: Oldham, M L.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: FE2]] | [[Category: FE2]] | ||
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[[Category: fatty acid]] | [[Category: fatty acid]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:23:17 2008'' |
Revision as of 15:23, 21 February 2008
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Insights from the X-ray crystal structure of coral 8R-lipoxygenase: calcium activation via A C2-like domain and a structural basis of product chirality
Overview
Lipoxygenases (LOXs) catalyze the regio- and stereospecific dioxygenation of polyunsaturated membrane-embedded fatty acids. We report here the 3.2 A resolution structure of 8R-LOX from the Caribbean sea whip coral Plexaura homomalla, a LOX isozyme with calcium dependence and the uncommon R chiral stereospecificity. Structural and spectroscopic analyses demonstrated calcium binding in a C2-like membrane-binding domain, illuminating the function of similar amino acids in calcium-activated mammalian 5-LOX, the key enzyme in the pathway to the pro-inflammatory leukotrienes. Mutation of Ca(2+)-ligating amino acids in 8R-LOX resulted not only in a diminished capacity to bind membranes, as monitored by fluorescence resonance energy transfer, but also in an associated loss of Ca(2+)-regulated enzyme activity. Moreover, a structural basis for R chiral specificity is also revealed; creation of a small oxygen pocket next to Gly(428) (Ala in all S-LOX isozymes) promoted C-8 oxygenation with R chirality on the activated fatty acid substrate.
About this Structure
2FNQ is a Single protein structure of sequence from Plexaura homomalla with and as ligands. This structure supersedes the now removed PDB entry 1ZQ4. Active as Arachidonate 8-lipoxygenase, with EC number 1.13.11.40 Full crystallographic information is available from OCA.
Reference
Insights from the X-ray crystal structure of coral 8R-lipoxygenase: calcium activation via a C2-like domain and a structural basis of product chirality., Oldham ML, Brash AR, Newcomer ME, J Biol Chem. 2005 Nov 25;280(47):39545-52. Epub 2005 Sep 14. PMID:16162493
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