https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Directing the heterologous production of specific cyanobacterial toxin variants https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31345 Escherichia coli to produce [ᴅ-Asp3]microcystin-LR and microcystin-LR. We assembled a 55 kb hybrid polyketide synthase/nonribosomal peptide synthetase gene cluster from Microcystis aeruginosa PCC 7806 using Red/ET recombineering and replaced the native promoters with an inducible PtetO promoter to yield microcystin titers superior to M. aeruginosa. The expression platform described herein can be tailored to heterologously produce a wide variety of microcystin variants, and potentially other cyanobacterial natural products of commercial relevance.]]> Wed 24 Nov 2021 15:51:49 AEDT ]]> Genome mining of a fungal endophyte of Taxus yunnanensis (Chinese yew) leads to the discovery of a novel azaphilone polyketide, lijiquinone https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39913 Ascomycete sp. F53 (F53), a fungal endophyte of the traditional Chinese medicinal plant Taxus yunnanensis (Chinese yew), revealed 35 putative specialized metabolite biosynthesis gene clusters, one of which encodes a rarely seen tandem polyketide synthase pathway with close homology to azaphilone biosynthesis pathways. A novel compound, lijiquinone 1, was subsequently isolated from F53 and structurally and functionally characterized. The m/z 385 [M + H+]+ compound, comprised of a cyclohexenone side group attached to a core bicyclic ring, displayed cytotoxicity against human myeloma cells (IC50 = 129 μM), as well as antifungal activity against Candida albicans (IC50 = 79 μM) and Cryptococcus albidus (IC50 = 141 μM). Our results suggest that enzymes encoded on the lij gene cluster are responsible for the synthesis of 1 and that the medicinal properties of T. yunnanensis could be partially mediated by this novel azaphilone. This study highlights the utility of combining traditional knowledge with contemporary genomic approaches for the discovery of new bioactive compounds.]]> Thu 30 Jun 2022 09:56:32 AEST ]]> A Pseudoalteromonas Clade with remarkable biosynthetic potential https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:40084 Thu 28 Jul 2022 14:10:01 AEST ]]>