View source for 4qnw


==Crystal structure of EasA, an old yellow enzyme from Aspergillus fumigatus==
<StructureSection load='4qnw' size='340' side='right'caption='[[4qnw]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4qnw]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Aspergillus_fumigatus_Af293 Aspergillus fumigatus Af293]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4QNW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4QNW 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]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FMN:FLAVIN+MONONUCLEOTIDE'>FMN</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4qnw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qnw OCA], [https://pdbe.org/4qnw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4qnw RCSB], [https://www.ebi.ac.uk/pdbsum/4qnw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4qnw ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/EASA_ASPFU EASA_ASPFU] Aldehyde reductase; part of the gene cluster that mediates the biosynthesis of fumiclavanine C, a fungal ergot alkaloid (PubMed:15933009, PubMed:22453123). DmaW catalyzes the first step of ergot alkaloid biosynthesis by condensing dimethylallyl diphosphate (DMAP) and tryptophan to form 4-dimethylallyl-L-tryptophan (PubMed:15870460). The second step is catalyzed by the methyltransferase easF that methylates 4-dimethylallyl-L-tryptophan in the presence of S-adenosyl-L-methionine, resulting in the formation of 4-dimethylallyl-L-abrine (By similarity). The catalase easC and the FAD-dependent oxidoreductase easE then transform 4-dimethylallyl-L-abrine to chanoclavine-I which is further oxidized by EasD in the presence of NAD(+), resulting in the formation of chanoclavine-I aldehyde (PubMed:20039019, PubMed:20526482, PubMed:21409592). EasA reduces chanoclavine-I aldehyde to dihydrochanoclavine-I aldehyde that spontaneously dehydrates to form 6,8-dimethyl-6,7-didehydroergoline (PubMed:20526482). EasG then catalyzes the reduction of 6,8-dimethyl-6,7-didehydroergoline to form festuclavine (PubMed:20526482). Hydrolysis of festuclavine by easM then leads to the formation of fumigaclavine B which is in turn acetylated by easN to fumigaclavine A (PubMed:26972831). Finally, easL catalyzes the conversion of fumigaclavine A into fumigaclavine C by attaching a dimethylallyl moiety to C-2 of the indole nucleus (PubMed:19672909).[UniProtKB:B6D5I7]<ref>PMID:15870460</ref> <ref>PMID:19672909</ref> <ref>PMID:20039019</ref> <ref>PMID:20526482</ref> <ref>PMID:21409592</ref> <ref>PMID:21898587</ref> <ref>PMID:22453123</ref> <ref>PMID:26972831</ref> 
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== Publication Abstract from PubMed ==
The Aspergillus fumigatus old yellow enzyme (OYE) EasA reduces chanoclavine-I aldehyde to dihydrochanoclavine aldehyde and works in conjunction with festuclavine synthase at the branchpoint for ergot alkaloid pathways. The crystal structure of the FMN-loaded EasA was determined to 1.8 A resolution. The active-site amino acids of OYE are conserved, supporting a similar mechanism for reduction of the alpha/beta-unsaturated aldehyde. The C-terminal tail of one monomer packs into the active site of a monomer in the next asymmetric unit, which is most likely to be a crystallization artifact and not a mechanism of self-regulation.

Structure of an Aspergillus fumigatus old yellow enzyme (EasA) involved in ergot alkaloid biosynthesis.,Chilton AS, Ellis AL, Lamb AL Acta Crystallogr F Struct Biol Commun. 2014 Oct 1;70(Pt 10):1328-32. doi:, 10.1107/S2053230X14018962. Epub 2014 Sep 25. PMID:25286934<ref>PMID:25286934</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 4qnw" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Aspergillus fumigatus Af293]]
[[Category: Large Structures]]
[[Category: Lamb AL]]