View source for 5yy2


==Crystal structure of AsqI with Zn==
<StructureSection load='5yy2' size='340' side='right'caption='[[5yy2]], [[Resolution|resolution]] 2.91&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5yy2]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Aspergillus_nidulans_FGSC_A4 Aspergillus nidulans FGSC A4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5YY2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5YY2 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.91&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></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=5yy2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5yy2 OCA], [https://pdbe.org/5yy2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5yy2 RCSB], [https://www.ebi.ac.uk/pdbsum/5yy2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5yy2 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ASQI_EMENI ASQI_EMENI] Cyclopenase; part of the gene cluster that mediates the biosynthesis of the aspoquinolone mycotoxins (PubMed:25251934, PubMed:30026518). Within the pathway, the cyclopenase asqI catalyzes the conversion of 4'-methoxycyclopenin into 4'-methoxyviridicatin (PubMed:30026518). Cyclopenin can also be converted into viridicatin by asqI (PubMed:30026518). The first step of the pathway is catalyzed by the nonribosomal pepdide synthetase asqK that condenses anthranilic acid and O-methyl-L-tyrosine to produce 4'-methoxycyclopeptin. 4'-methoxycyclopeptin is then converted to 4'-methoxydehydrocyclopeptin by the ketoglutarate-dependent dioxygenase asqJ. AsqJ also converts its first product 4'-methoxydehydrocyclopeptin to 4'-methoxycyclopenin. The following conversion of 4'-methoxycyclopenin into 4'-methoxyviridicatin is catalyzed by the cyclopenase asqI. 4'-methoxyviridicatin is the precursor of quinolone natural products, and is further converted to quinolinone B. The prenyltransferase asqH1 then catalyzes the canonical Friedel-Crafts alkylation of quinolinone B with dimethylallyl cation to yield dimethylallyl quinolone, which is subjected to FAD-dependent dehydrogenation by the FAD-linked oxidoreductase asqF to yield conjugated aryl diene. The delta(3') double bond then serves as the site of the second alkylation with DMAPP catalyzed by the prenyltransferase asqH2 to yield a carbenium ion intermediate, which can be attacked by H(2)O to yield a styrenyl quinolone containing a C3'-hydroxyprenyl chain. The FAD-dependent monooxygenase asqG performs epoxidation of the terminal C7'-C8' olefin. Finally, after dehydratation of the epoxide at C3 by asqC, the quinolone epoxide rearrangement protein asqO catalyzes an enzymatic 3-exo-tet cyclization to yield the cyclopropyl-THF ring system in aspoquinolone (Probable).<ref>PMID:25251934</ref> <ref>PMID:30026518</ref> 
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Aspergillus nidulans FGSC A4]]
[[Category: Large Structures]]
[[Category: Hara K]]
[[Category: Hashimoto H]]
[[Category: Kishimoto S]]
[[Category: Watanabe K]]