Identification and Characterization of a New Type III Polyketide Synthase from a Marine Yeast, Naganishia uzbekistanensis

Abstract

A putative Type III Polyketide synthase (PKSIII) encoding gene was identified from a marine yeast, Naganishia uzbekistanensis strain Mo29 (UBOCC-A-208024) (formerly named as Cryptococcus sp.) isolated from deep-sea hydrothermal vents. This gene is part of a distinct phylogenetic branch compared to all known terrestrial fungal sequences. This new gene encodes a C-terminus extension of 74 amino acids compared to other known PKSIII proteins like Neurospora crassa. Full-length and reduced versions of this PKSIII were successfully cloned and overexpressed in a bacterial host, Escherichia coli BL21 (DE3). Both proteins showed the same activity, suggesting that additional amino acid residues at the C-terminus are probably not required for biochemical functions. We demonstrated by LC-ESI-MS/MS that these two recombinant PKSIII proteins could only produce tri- and tetraketide pyrones and alkylresorcinols using only long fatty acid chain from C8 to C16 acyl-CoAs as starter units, in presence of malonyl-CoA. In addition, we showed that some of these molecules exhibit cytotoxic activities against several cancer cell lines.

Marine natural products

“…314 Investigation of deep sea, hydrothermal ventderived Naganishia uzbekistanesis revealed the presence of a PKS gene that was phylogenetically unique and encodes Cterminus extension of amino acids. 315 Flavin-dependent monooxygenases have been characterised and implicated in catalytic control of a crucial semi-pinacol rearrangement in biosynthesis of the indole alkaloids notoamides. 316 Amongst the range of reviews published on specic compound classes isolated from marine fungi were ones on terpenoids, 317 meroterpenoids 318 and alkaloids.…”

Isolation, Phylogenetic and Gephyromycin Metabolites Characterization of New Exopolysaccharides-Bearing Antarctic Actinobacterium from Feces of Emperor Penguin

“…According to the obtained prediction result, total five BGCs were found in the genome of strain NJES-13, including a 44.5 kb long type III polyketide synthase (T3PKS) cluster with 100% similarity, as well as one 47.4 kb long type I polyketide synthase (T1PKS) cluster, two NRPS-like clusters of 43.4 and 42.0 kb, respectively, and one 27.8 kb long beta-lactone cluster. These findings indicate that strain NJES-13 possesses great potential to produce novel bioactive metabolites [ 33 , 34 , 35 , 36 ]. But unlike its closest relative, both T3PKS and T1PKS gene clusters were absent in the type strain of Mobilicoccus pelagius .…”

Characterization of Bioactivities and Biosynthesis of Angucycline/Angucyclinone Derivatives Derived from Gephyromycinifex aptenodytis gen. nov., sp. nov.

“…The prediction of the biosynthetic gene clusters (BGCs) for secondary metabolite synthesis was performed using the Secondary Metabolite Analysis Shell (antiSMASH) version 6.0.1 [27,[44][45][46] based on the whole genome sequence of strain NJES-13 T [11]. The genome sequence data were also analyzed by Blast2GO tool [47,48] to help to predict the po-tential cluster gene functions and to confirm genetic functions by manual BLASTx/BLASTp searching in NCBI non-redundant (NR) protein sequence database.…”