Fusarin C


Fusarin C



The mycotoxin fusarin C has been isolated from F. graminearum, Fusarium moniliforme (= F. verticillioides, teleomorph Gibberella fujikuroi = G. moniliformis) and Fusarium venenatum. Structural characterization of the compound and isotope labelling experiments (13C acetate) suggested a mixed biosynthetic origin by including both polyketide and amino acid motifs (Gelderblom et al., 1984). The presence of methyl groups directly on the polyketide chain suggested that the involved PKS would pose a carbon methyltransferase domain (CMeT). The fusarin C PKS (fusA or FUSS) was isolated by probing a cDNA library with a probe made with degenerated primers targeted against the CMeT domain using F. moniliforme cDNA as temple. Sequence analysis of the deduced PKS amino acid sequence (3951 aa) revealed that the PKS in fact was a hybrid of a PKS and a non-ribosomal peptide synthase (PKS-NRPS) with the following domain architecture: KS-AT-DH-CMeT-ER?-KR-ACP-C-A-T-R. Where the PKS domains (KS-AT-DH-CMeT-ER?-KR-ACP) are responsible for synthesis of the linear heptaketide chain, while the NRPS domains (C-A-T-R) adds a homoserin to the PKS chain. Targeted replacement of fusA confirmed that it was required for the biosynthesis of fusarin C and also allowed for the formulation of a model for the biosynthesis of the compound (Figure 12).


Later an analysis of the F. graminearum PH-1 genome has re-identified the fusA PKS-NRPS, renamed FgPKS10 (FG12100) in (Gaffoor et al., 2005), and targeted replacement confirmed the results (Song et al., 2004). The genes encoding the proposed modifying enzymes have not been identified; however the genes surrounding the fusA gene in F. graminearum includes both cytochrome P450-dependent monooxygenases, a FAD/FMN-dependent dehydrogenase, a S-adenosyl methionine-dependent O-methyl transferase and an acyl hydrolase suggesting the existence of a gene cluster (Rees et al., 2007).


bulletGelderblom,W.C.A., Marasas,W.F.O., Steyn,P.S., Thiel,P.G., Vandermerwe,K.J., Vanrooyen,P.H. et al. (1984) Structure Elucidation of Fusarin-C, A Mutagen Produced by Fusarium-Moniliforme. Journal of the Chemical Society-Chemical Communications: 122-124.
bulletGaffoor,I., Brown,D.W., Plattner,R., Proctor,R.H., Qi,W.H., and Trail,F. (2005) Functional analysis of the polyketide synthase genes in the filamentous fungus Gibberella zeae (Anamorph Fusarium graminearum). Eukaryotic Cell 4: 1926-1933.
bulletSong,Z.S., Cox,R.J., Lazarus,C.M., and Simpson,T.J. (2004) Fusarin C biosynthesis in Fusarium moniliforme and Fusarium venenatum. Chembiochem 5: 1196-1203.

Rees,D.O., Bushby,N., Cox,R.J., Harding,J.R., Simpson,T.J., and Willis,C.L. (2007) Synthesis of [1,2-C-13(2), N-15]-L-homoserine and its incorporation by the PKS-NRPS system of Fusarium moniliforme into the mycotoxin fusarin C. Chembiochem 8: 46-50.



Home | Aflatoxin | Aurofusarin | Zearalenone | Fumonisins | Fusarin C | Bikaverin

Dette sted blev sidst opdateret 10. July 2010