1eyq

<StructureSection load='1eyq' size='340' side='right' caption='[[1eyq]], [[Resolution|resolution]] 1.85&Aring;' scene=''>

<table><tr><td colspan='2'>[[1eyq]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Alfalfa Alfalfa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EYQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1EYQ FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NAR:NARINGENIN'>NAR</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1eyp|1eyp]]</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Chalcone_isomerase Chalcone isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.5.1.6 5.5.1.6] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1eyq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eyq OCA], [http://pdbe.org/1eyq PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1eyq RCSB], [http://www.ebi.ac.uk/pdbsum/1eyq PDBsum]</span></td></tr>

[[http://www.uniprot.org/uniprot/CFI1_MEDSA CFI1_MEDSA]] Catalyzes the intramolecular cyclization of bicyclic chalcones into tricyclic (S)-flavanones. Responsible for the isomerization of 4,2',4',6'-tetrahydroxychalcone (also termed chalcone) into naringenin.<ref>PMID:10966651</ref> <ref>PMID:11955065</ref> <ref>PMID:11698411</ref>

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ey/1eyq_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

Chalcone isomerase (CHI) catalyzes the intramolecular cyclization of chalcone synthesized by chalcone synthase (CHS) into (2S)-naringenin, an essential compound in the biosynthesis of anthocyanin pigments, inducers of Rhizobium nodulation genes, and antimicrobial phytoalexins. The 1.85 A resolution crystal structure of alfalfa CHI in complex with (2S)-naringenin reveals a novel open-faced beta-sandwich fold. Currently, proteins with homologous primary sequences are found only in higher plants. The topology of the active site cleft defines the stereochemistry of the cyclization reaction. The structure and mutational analysis suggest a mechanism in which shape complementarity of the binding cleft locks the substrate into a constrained conformation that allows the reaction to proceed with a second-order rate constant approaching the diffusion controlled limit. This structure raises questions about the evolutionary history of this structurally unique plant enzyme.

Structure and mechanism of the evolutionarily unique plant enzyme chalcone isomerase.,Jez JM, Bowman ME, Dixon RA, Noel JP Nat Struct Biol. 2000 Sep;7(9):786-91. PMID:10966651<ref>PMID:10966651</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1eyq" style="background-color:#fffaf0;"></div>

[[Category: Alfalfa]]

[[Category: Chalcone isomerase]]

[[Category: Bowman, M E]]

[[Category: Dixon, R A]]

[[Category: Jez, J M]]

[[Category: Noel, J P]]

[[Category: Isomerase]]