5eas

<table><tr><td colspan='2'>[[5eas]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/American_tobacco American tobacco]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5EAS OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=5EAS FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=5eas FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5eas OCA], [http://pdbe.org/5eas PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5eas RCSB], [http://www.ebi.ac.uk/pdbsum/5eas PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5eas ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/5EAS_TOBAC 5EAS_TOBAC]] Catalyzes the cyclization of trans,trans-farnesyl diphosphate (FPP) to the bicyclic intermediate 5-epi-aristolochene, initial step in the conversion of FPP to the sesquiterpenoid antifungal phytoalexin capsidiol. Produces germacrene A as an enzyme-bound intermediate that is not released by the enzyme, but is further cyclized to produce the bicyclic 5-epi-aristolochene.

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== Publication Abstract from PubMed ==

Terpene cyclases catalyze the synthesis of cyclic terpenes with 10-, 15-, and 20-carbon acyclic isoprenoid diphosphates as substrates. Plants have been a source of these natural products by providing a homologous set of terpene synthases. The crystal structures of 5-epi-aristolochene synthase, a sesquiterpene cyclase from tobacco, alone and complexed separately with two farnesyl diphosphate analogs were analyzed. These structures reveal an unexpected enzymatic mechanism for the synthesis of the bicyclic product, 5-epi-aristolochene, and provide a basis for understanding the stereochemical selectivity displayed by other cyclases in the biosynthesis of pharmacologically important cyclic terpenes. As such, these structures provide templates for the engineering of novel terpene cyclases.

Structural basis for cyclic terpene biosynthesis by tobacco 5-epi-aristolochene synthase.,Starks CM, Back K, Chappell J, Noel JP Science. 1997 Sep 19;277(5333):1815-20. PMID:9295271<ref>PMID:9295271</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 5eas" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: American tobacco]]

[[Category: Back, K]]

[[Category: Chappell, J]]

[[Category: Noel, J P]]

[[Category: Starks, C M]]

[[Category: 5-epi-aristolochene synthase]]

[[Category: Natural products biosynthesis]]