RESUMO
Members of the genus Fusarium produce a plethora of bioactive secondary metabolites, which can be harmful to humans and animals or have potential in drug development. In this study we have performed comparative analyses of polyketide synthases (PKSs) and non-ribosomal peptide synthetases (NRPSs) from ten different Fusarium species including F. graminearum (two strains), F. verticillioides, F. solani, F. culmorum, F. pseudograminearum, F. fujikuroi, F. acuminatum, F. avenaceum, F. equiseti, and F. oxysporum (12 strains). This led to identification of 52 NRPS and 52 PKSs orthology groups, respectively, and although not all PKSs and NRPSs are assumed to be intact or functional, the analyses illustrate the huge secondary metabolite potential in Fusarium. In our analyses we identified a core collection of eight NRPSs (NRPS2-4, 6, 10-13) and two PKSs (PKS3 and PKS7) that are conserved in all strains analyzed in this study. The identified PKSs and NRPSs were named based on a previously developed classification system (www.FusariumNRPSPKS.dk). We suggest this system be used when PKSs and NRPSs have to be classified in future sequenced Fusarium strains. This system will facilitate identification of orthologous and non-orthologous NRPSs and PKSs from newly sequenced Fusarium genomes and will aid the scientific community by providing a common nomenclature for these two groups of genes/enzymes.
Assuntos
Fusarium/genética , Peptídeo Sintases/classificação , Peptídeo Sintases/genética , Policetídeo Sintases/classificação , Policetídeo Sintases/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/classificação , Proteínas Fúngicas/genética , Fusarium/química , Fusarium/classificação , Fusarium/enzimologia , Genes Fúngicos , Filogenia , Terminologia como AssuntoRESUMO
The closely related species Fusarium graminearum and Fusarium pseudograminearum differ in that each contains a gene cluster with a polyketide synthase (PKS) and a nonribosomal peptide synthetase (NRPS) that is not present in the other species. To identify their products, we deleted PKS6 and NRPS7 in F. graminearum and NRPS32 in F. pseudograminearum. By comparing the secondary metabolite profiles of the strains we identified the resulting product in F. graminearum as fusaristatin A, and as W493 A and B in F. pseudograminearum. These lipopeptides have previously been isolated from unidentified Fusarium species. On the basis of genes in the putative gene clusters we propose a model for biosynthesis where the polyketide product is shuttled to the NPRS via a CoA ligase and a thioesterase in F. pseudograminearum. In F. graminearum the polyketide is proposed to be directly assimilated by the NRPS.
