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| | <StructureSection load='5dhi' size='340' side='right'caption='[[5dhi]], [[Resolution|resolution]] 2.25Å' scene=''> | | <StructureSection load='5dhi' size='340' side='right'caption='[[5dhi]], [[Resolution|resolution]] 2.25Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5dhi]] 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=5DHI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5DHI FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5dhi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Nicotiana_tabacum Nicotiana tabacum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5DHI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5DHI FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.25Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5dhk|5dhk]]</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='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">EAS3, EAS4 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4097 American tobacco])</td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5dhi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5dhi OCA], [https://pdbe.org/5dhi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5dhi RCSB], [https://www.ebi.ac.uk/pdbsum/5dhi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5dhi ProSAT]</span></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/5-epiaristolochene_synthase 5-epiaristolochene synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.3.61 4.2.3.61] </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=5dhi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5dhi OCA], [http://pdbe.org/5dhi PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5dhi RCSB], [http://www.ebi.ac.uk/pdbsum/5dhi PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5dhi ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[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. | + | [https://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. |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: 5-epiaristolochene synthase]] | |
| - | [[Category: American tobacco]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Kersten, R D]] | + | [[Category: Nicotiana tabacum]] |
| - | [[Category: Noel, J P]] | + | [[Category: Kersten RD]] |
| - | [[Category: Active site alkylation]] | + | [[Category: Noel JP]] |
| - | [[Category: Farnesylation]]
| + | |
| - | [[Category: Lyase]]
| + | |
| - | [[Category: Sesquiterpene synthase]]
| + | |
| Structural highlights
Function
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.
Publication Abstract from PubMed
Terpenes are ubiquitous natural chemicals with diverse biological functions spanning all three domains of life. In specialized metabolism, the active sites of terpene synthases (TPSs) evolve in shape and reactivity to direct the biosynthesis of a myriad of chemotypes for organismal fitness. As most terpene biosynthesis mechanistically involves highly reactive carbocationic intermediates, the protein surfaces catalyzing these cascade reactions possess reactive regions possibly prone to premature carbocation capture and potentially enzyme inactivation. Here, we show using proteomic and X-ray crystallographic analyses that cationic intermediates undergo capture by conserved active site residues leading to inhibitory self-alkylation. Moreover, the level of cation-mediated inactivation increases with mutation of the active site, upon changes in the size and structure of isoprenoid diphosphate substrates, and alongside increases in reaction temperatures. TPSs that individually synthesize multiple products are less prone to self-alkylation then TPSs possessing relatively high product specificity. In total, the results presented suggest that mechanism-based alkylation represents an overlooked mechanistic pressure during the evolution of cation-derived terpene biosynthesis.
Mechanism-Based Post-Translational Modification and Inactivation in Terpene Synthases.,Kersten RD, Diedrich JK, Yates JR 3rd, Noel JP ACS Chem Biol. 2015 Sep 17. PMID:26378620[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kersten RD, Diedrich JK, Yates JR 3rd, Noel JP. Mechanism-Based Post-Translational Modification and Inactivation in Terpene Synthases. ACS Chem Biol. 2015 Sep 17. PMID:26378620 doi:http://dx.doi.org/10.1021/acschembio.5b00539
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