5oa8: Difference between revisions
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The | ==Fe(II)/(alpha)ketoglutarate-dependent dioxygenase AsqJ_V72I mutant in complex with demethylated cyclopeptin (1d)== | ||
<StructureSection load='5oa8' size='340' side='right' caption='[[5oa8]], [[Resolution|resolution]] 1.75Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[5oa8]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5OA8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5OA8 FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=58L:DEMETHYLATED+CYCLOPEPTIN'>58L</scene>, <scene name='pdbligand=AKG:2-OXOGLUTARIC+ACID'>AKG</scene>, <scene name='pdbligand=NI:NICKEL+(II)+ION'>NI</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5dap|5dap]]</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=5oa8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5oa8 OCA], [http://pdbe.org/5oa8 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5oa8 RCSB], [http://www.ebi.ac.uk/pdbsum/5oa8 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5oa8 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/ASQJ_EMENI ASQJ_EMENI]] Iron/alpha-ketoglutarate-dependent dioxygenase; part of the gene cluster that mediates the biosynthesis of the aspoquinolone mycotoxins (PubMed:25251934, PubMed:26553478). The first stage is catalyzed by the nonribosomal pepdide synthetase asqK that condenses anthranilic acid and O-methyl-L-tyrosine to produce 4'-methoxycyclopeptin (PubMed:25251934). AsqK is also able to use anthranilic acid and L-phenylalanine as substrates to produce cyclopeptin, but at a tenfold lower rate (PubMed:25251934). 4'-methoxycyclopeptin is then converted to 4'-methoxydehydrocyclopeptin by the ketoglutarate-dependent dioxygenase asqJ through dehydrogenation to form a double bond between C-alpha and C-beta of the O-methyltyrosine side chain (PubMed:25251934, PubMed:26553478). AsqJ also converts its first product 4'-methoxydehydrocyclopeptin to 4'-methoxycyclopenin (PubMed:25251934). AsqJ is a very unique dioxygenase which is capable of catalyzing radical-mediated dehydrogenation and epoxidation reactions sequentially on a 6,7-benzo-diazepinedione substrate in the 4'-methoxyviridicatin biosynthetic pathway (PubMed:25251934). The following conversion of 4'-methoxycyclopenin into 4'-methoxyviridicatin proceeds non-enzymatically (PubMed:25251934). AsqJ is also capable of converting cyclopeptin into dehydrocyclopeptin and cyclopenin in a sequential fashion (PubMed:25251934). Cyclopenin can be converted into viridicatin non-enzymatically (PubMed:25251934). 4'-methoxyviridicatin likely acts as a precursor of quinolone natural products, such as aspoquinolones, peniprequinolones, penigequinolones, and yaequinolones (PubMed:25251934). Further characterization of the remaining genes in the cluster has still to be done to determine the exact identity of quinolone products this cluster is responsible for biosynthesizing (PubMed:25251934).<ref>PMID:25251934</ref> <ref>PMID:26553478</ref> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The recently discovered Fe(II)/alpha-ketoglutarate-dependent dioxygenase AsqJ from Aspergillus nidulans stereoselectively catalyzes a multistep synthesis of quinolone alkaloids, natural products with significant biomedical applications. To probe molecular mechanisms of this elusive catalytic process, we combine here multi-scale quantum and classical molecular simulations with X-ray crystallography, and in vitro biochemical activity studies. We discover that methylation of the substrate is essential for the activity of AsqJ, establishing molecular strain that fine-tunes pi-stacking interactions within the active site. To rationally engineer AsqJ for modified substrates, we amplify dispersive interactions within the active site. We demonstrate that the engineered enzyme has a drastically enhanced catalytic activity for non-methylated surrogates, confirming our computational data and resolved high-resolution X-ray structures at 1.55 A resolution. Our combined findings provide crucial mechanistic understanding of the function of AsqJ and showcase how combination of computational and experimental data enables to rationally engineer enzymes. | |||
Catalytic mechanism and molecular engineering of quinolone biosynthesis in dioxygenase AsqJ.,Mader SL, Brauer A, Groll M, Kaila VRI Nat Commun. 2018 Mar 21;9(1):1168. doi: 10.1038/s41467-018-03442-2. PMID:29563492<ref>PMID:29563492</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
[[Category: | <div class="pdbe-citations 5oa8" style="background-color:#fffaf0;"></div> | ||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Braeuer, A]] | |||
[[Category: Groll, M]] | [[Category: Groll, M]] | ||
[[Category: | [[Category: Kaila, V R.I]] | ||
[[Category: Antibiotic]] | |||
[[Category: Catalytic mechanism]] | |||
[[Category: Desaturase]] | |||
[[Category: Molecular engineering]] | |||
[[Category: Mutagenesis]] | |||
[[Category: Oxidoreductase]] | |||
[[Category: Pi-stacking]] | |||
[[Category: Quinolone biosynthesis]] | |||