2brj
From Proteopedia
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| - | [[Image:2brj.gif|left|200px]]<br /><applet load="2brj" size=" | + | [[Image:2brj.gif|left|200px]]<br /><applet load="2brj" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2brj, resolution 1.50Å" /> | caption="2brj, resolution 1.50Å" /> | ||
'''X-RAY STRUCTURE OF THE ALLENE OXIDE CYCLASE FROM ARABIDOPSIS THALIANA'''<br /> | '''X-RAY STRUCTURE OF THE ALLENE OXIDE CYCLASE FROM ARABIDOPSIS THALIANA'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 2BRJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana] with GOL as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Allene-oxide_cyclase Allene-oxide cyclase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.99.6 5.3.99.6] Known structural/functional Site: <scene name='pdbsite=AC1:Gol Binding Site For Chain A'>AC1</scene>. Full crystallographic information is available from [http:// | + | 2BRJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana] with <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Allene-oxide_cyclase Allene-oxide cyclase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.99.6 5.3.99.6] Known structural/functional Site: <scene name='pdbsite=AC1:Gol+Binding+Site+For+Chain+A'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BRJ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: transit peptide]] | [[Category: transit peptide]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 10:27:06 2008'' |
Revision as of 08:27, 3 February 2008
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X-RAY STRUCTURE OF THE ALLENE OXIDE CYCLASE FROM ARABIDOPSIS THALIANA
Overview
We describe the crystallization and structure elucidation of Arabidopsis, thaliana allene oxide cyclase 2 (AOC2), a key enzyme in the biosynthesis, of jasmonates. In a coupled reaction with allene oxide synthase, AOC2, releases the first cyclic and biologically active metabolite, 12-oxo-phytodienoic acid (OPDA). AOC2 (AT3G25770) folds into an, eight-stranded antiparallel beta-barrel with a C-terminal partial helical, extension. The protein forms a hydrophobic binding cavity with two, distinct polar patches. AOC2 is trimeric in crystals, in vitro and in, planta. Based on the observed folding pattern, we assigned AOC2 as a low, molecular weight member of the lipocalin family with enzymatic activity in, plants. We determined the binding position of the competitive inhibitor, vernolic acid (a substrate analog) in the binding pocket. Based on models, for bound substrate 12,13-epoxy-9,11,15-octadecatrienoic acid and product, OPDA, we propose a reaction scheme that explains the influence of the C15, double bond on reactivity. Reaction is promoted by anchimeric assistance, through a conserved Glu residue. The transition state with a pentadienyl, carbocation and an oxyanion is stabilized by a strongly bound water, molecule and favorable pi-pi interactions with aromatic residues in the, cavity. Stereoselectivity results from steric restrictions to the, necessary substrate isomerizations imposed by the protein.
About this Structure
2BRJ is a Single protein structure of sequence from Arabidopsis thaliana with as ligand. Active as Allene-oxide cyclase, with EC number 5.3.99.6 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
The crystal structure of Arabidopsis thaliana allene oxide cyclase: insights into the oxylipin cyclization reaction., Hofmann E, Zerbe P, Schaller F, Plant Cell. 2006 Nov;18(11):3201-17. Epub 2006 Nov 3. PMID:17085685
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