View source for 6pvi


==Crystal structure of PhqK in complex with paraherquamide L==
<StructureSection load='6pvi' size='340' side='right'caption='[[6pvi]], [[Resolution|resolution]] 2.09&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6pvi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Penicillium_fellutanum Penicillium fellutanum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6PVI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6PVI 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]] 2.093&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=OZ7:(8aS,13S,13aR,14aS)-4,4,13,15,15-pentamethyl-12,13,14,14a,15,16-hexahydro-4H,8H,9H,11H-8a,13a-(epiminomethano)[1,4]dioxepino[2,3-a]indolizino[6,7-h]carbazol-17-one'>OZ7</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=6pvi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6pvi OCA], [https://pdbe.org/6pvi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6pvi RCSB], [https://www.ebi.ac.uk/pdbsum/6pvi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6pvi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PHQK_PENFE PHQK_PENFE] FAD-dependent monooxygenase; part of the gene cluster that mediates the biosynthesis of paraherquamide, a fungal indole alkaloid that belongs to a family of natural products containing a characteristic bicyclo[2.2.2]diazaoctane core (PubMed:23213353). The first steps in the biosynthesis of paraherquamide is the production of the beta-methyl-proline precursor from L-isoleucine (Probable). They require oxidation of a terminally hydroxylated L-isoleucine to the corresponding aldehyde by enzymes which have still to be identified (Probable). Spontaneous cyclization and dehydration would yield the 4-methyl pyrolline-5-carboxylic acid, which is then reduced by the pyrroline-5-carboxylate reductase phqD leading to the beta-methyl-proline precursor (Probable). The next step of paraherquamide biosynthesis involves coupling of beta-methyl-proline and L-tryptophan by the bimodular NRPS phqB, to produce a monooxopiperazine intermediate (Probable). The reductase (R) domain of phqB utilizes NADPH for hydride transfer to reduce the thioester bond of the T domain-tethered linear dipeptide to a hemithioaminal intermediate, which spontaneously cleaves the C-S bond to release the aldehyde product (PubMed:31548667). This compound undergoes spontaneous cyclization and dehydration to give a dienamine which is reverse prenylated at C-2 by the reverse prenyltransferase phqJ (Probable). The other prenyltransferase present in the cluster, phqI may be a redundant gene in the pathway (Probable). During biosynthetic assembly, the key step to produce the polycyclic core is catalyzed by the bifunctional reductase and intramolecular [4+2] Diels-Alderase, phqE, resulting in formation of the [2.2.2] diazaoctane intermediate preparaherquamide (PubMed:31548667). Following formation of preparaherquamide, an indole 2,3-epoxidation-initiated pinacol-like rearrangement is catalyzed by the phqK FAD-dependent monooxygenase (Probable). The prenyltransferase phqA, the cytochrome P450 monooxygenase phqL, and the FAD-linked oxidoreductase phqH (or the cytochrome P450 monooxygenase phqM), are proposed to be involved in the formation of the pyran ring (Probable). The FAD-dependent monooxygenase phqK is likely responsible for generation of the spiro-oxindole, and the N-methylation is likely mediated by the phqN methyltransferase leading to the isolable natural product paraherquamide F (Probable). However, the order of these biosynthetic steps has still to be determined (Probable). In late-stage paraherquamide biosynthesis, the third P450 monooxygenase, phqO, is probably responsible for the C-14 hydroxylation, transforming paraherquamide F to paraherquamide G, and paraherquamide E to the final product paraherquamide A (Probable). The expansion from the 6-membered ring pyran (in paraherquamides F and G) to the 7-membered dioxepin ring (in paraherquamides A and E) represents a poorly understood but intriguing process that probably involves the 2-oxoglutarate-dependent dioxygenase phqC (Probable). Finally, the remaining members of the paraherquamide cluster, including phqI as well as phqM (or phqH), do not have a clearly prescribed role and appear to be redundant (Probable).<ref>PMID:23213353</ref> <ref>PMID:31548667</ref> <ref>PMID:23213353</ref> 

==See Also==
*[[Monooxygenase 3D structures|Monooxygenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Penicillium fellutanum]]
[[Category: Fraley AE]]
[[Category: Sherman DH]]
[[Category: Smith JL]]