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[[Image: | ==CRYSTAL STRUCTURES OF THE ARABIDOPSIS CINNAMYL ALCOHOL DEHYDROGENASES ATCAD5== | ||
<StructureSection load='2cf6' size='340' side='right' caption='[[2cf6]], [[Resolution|resolution]] 2.60Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2cf6]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2CF6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2CF6 FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NAP:NADP+NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NAP</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2cf5|2cf5]]</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Cinnamyl-alcohol_dehydrogenase Cinnamyl-alcohol dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.195 1.1.1.195] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2cf6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2cf6 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2cf6 RCSB], [http://www.ebi.ac.uk/pdbsum/2cf6 PDBsum]</span></td></tr> | |||
<table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/cf/2cf6_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The cinnamyl alcohol dehydrogenase (CAD) multigene family in planta encodes proteins catalyzing the reductions of various phenylpropenyl aldehyde derivatives in a substrate versatile manner, and whose metabolic products are the precursors of structural lignins, health-related lignans, and various other metabolites. In Arabidopsis thaliana, the two isoforms, AtCAD5 and AtCAD4, are the catalytically most active being viewed as mainly involved in the formation of guaiacyl/syringyl lignins. In this study, we determined the crystal structures of AtCAD5 in the apo-form and as a binary complex with NADP+, respectively, and modeled that of AtCAD4. Both AtCAD5 and AtCAD4 are dimers with two zinc ions per subunit and belong to the Zn-dependent medium chain dehydrogenase/reductase (MDR) superfamily, on the basis of their overall 2-domain structures and distribution of secondary structural elements. The catalytic Zn2+ ions in both enzymes are tetrahedrally coordinated, but differ from those in horse liver alcohol dehydrogenase since the carboxyl side-chain of Glu70 is ligated to Zn2+ instead of water. Using AtCAD5, site-directed mutagenesis of Glu70 to alanine resulted in loss of catalytic activity, thereby indicating that perturbation of the Zn2+ coordination was sufficient to abolish catalytic activity. The substrate-binding pockets of both AtCAD5 and AtCAD4 were also examined, and found to be significantly different and smaller compared to that of a putative aspen sinapyl alcohol dehydrogenase (SAD) and a putative yeast CAD. While the physiological roles of the aspen SAD and the yeast CAD are uncertain, they nevertheless have a high similarity in the overall 3D structures to AtCAD5 and 4. With the bona fide CAD's from various species, nine out of the twelve residues which constitute the proposed substrate-binding pocket were, however, conserved. This is provisionally considered as indicative of a characteristic fingerprint for the CAD family. | |||
Crystal structures and catalytic mechanism of the Arabidopsis cinnamyl alcohol dehydrogenases AtCAD5 and AtCAD4.,Youn B, Camacho R, Moinuddin SG, Lee C, Davin LB, Lewis NG, Kang C Org Biomol Chem. 2006 May 7;4(9):1687-97. Epub 2006 Apr 4. PMID:16633561<ref>PMID:16633561</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Alcohol dehydrogenase|Alcohol dehydrogenase]] | *[[Alcohol dehydrogenase|Alcohol dehydrogenase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Arabidopsis thaliana]] | [[Category: Arabidopsis thaliana]] | ||
[[Category: Cinnamyl-alcohol dehydrogenase]] | [[Category: Cinnamyl-alcohol dehydrogenase]] | ||
Revision as of 13:15, 29 September 2014
CRYSTAL STRUCTURES OF THE ARABIDOPSIS CINNAMYL ALCOHOL DEHYDROGENASES ATCAD5CRYSTAL STRUCTURES OF THE ARABIDOPSIS CINNAMYL ALCOHOL DEHYDROGENASES ATCAD5
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe cinnamyl alcohol dehydrogenase (CAD) multigene family in planta encodes proteins catalyzing the reductions of various phenylpropenyl aldehyde derivatives in a substrate versatile manner, and whose metabolic products are the precursors of structural lignins, health-related lignans, and various other metabolites. In Arabidopsis thaliana, the two isoforms, AtCAD5 and AtCAD4, are the catalytically most active being viewed as mainly involved in the formation of guaiacyl/syringyl lignins. In this study, we determined the crystal structures of AtCAD5 in the apo-form and as a binary complex with NADP+, respectively, and modeled that of AtCAD4. Both AtCAD5 and AtCAD4 are dimers with two zinc ions per subunit and belong to the Zn-dependent medium chain dehydrogenase/reductase (MDR) superfamily, on the basis of their overall 2-domain structures and distribution of secondary structural elements. The catalytic Zn2+ ions in both enzymes are tetrahedrally coordinated, but differ from those in horse liver alcohol dehydrogenase since the carboxyl side-chain of Glu70 is ligated to Zn2+ instead of water. Using AtCAD5, site-directed mutagenesis of Glu70 to alanine resulted in loss of catalytic activity, thereby indicating that perturbation of the Zn2+ coordination was sufficient to abolish catalytic activity. The substrate-binding pockets of both AtCAD5 and AtCAD4 were also examined, and found to be significantly different and smaller compared to that of a putative aspen sinapyl alcohol dehydrogenase (SAD) and a putative yeast CAD. While the physiological roles of the aspen SAD and the yeast CAD are uncertain, they nevertheless have a high similarity in the overall 3D structures to AtCAD5 and 4. With the bona fide CAD's from various species, nine out of the twelve residues which constitute the proposed substrate-binding pocket were, however, conserved. This is provisionally considered as indicative of a characteristic fingerprint for the CAD family. Crystal structures and catalytic mechanism of the Arabidopsis cinnamyl alcohol dehydrogenases AtCAD5 and AtCAD4.,Youn B, Camacho R, Moinuddin SG, Lee C, Davin LB, Lewis NG, Kang C Org Biomol Chem. 2006 May 7;4(9):1687-97. Epub 2006 Apr 4. PMID:16633561[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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