Genetic manipulation of the Fusarium fujikuroi fusarin gene cluster yields insight into the complex regulation and fusarin biosynthetic pathway.
In this work, the biosynthesis and regulation of the polyketide synthase/nonribosomal peptide synthetase (PKS/NRPS)-derived mutagenic mycotoxin fusarin C was studied in the fungus Fusarium fujikuroi. The fusarin gene cluster consists of nine genes (fus1-fus9) that are coexpressed under high-nitrogen and acidic pH conditions. Chromatin immunoprecipitation revealed a correlation between high expression and enrichment of activating H3K9-acetylation marks under inducing conditions. We provide evidence that only four genes are sufficient for the biosynthesis. The combination of genetic engineering with nuclear magnetic resonance and mass-spectrometry-based structure elucidation allowed the discovery of the putative fusarin biosynthetic pathway. Surprisingly, we indicate that PKS/NRPS releases its product with an open ring structure, probably as an alcohol. Our data indicate that 2-pyrrolidone ring closure, oxidation at C-20, and, finally, methylation at C-20 are catalyzed by Fus2, Fus8, and Fus9, respectively.
Institute for Biology and Biotechnology of Plants, Westfälische Wilhelms-Universität Münster, Schlossplatz 8, Münster 48143, Germany.
Eva-Maria
EM
Niehaus
Karin
K
Kleigrewe
Philipp
P
Wiemann
Lena
L
Studt
Christian M K
CM
Sieber
Lanelle R
LR
Connolly
Michael
M
Freitag
Ulrich
U
Güldener
Bettina
B
Tudzynski
Hans-Ulrich
HU
Humpf
D000107:Acetylation; D053898:Biosynthetic Pathways; D005670:Fusarium / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D005818:Genetic Engineering; D005810:Multigene Family; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism*; D011090:Polyenes / Q000737:chemistry / Q000378:metabolism*; D048630:Polyketide Synthases / Q000235:genetics / Q000378:metabolism*
D011090:Polyenes; D048630:Polyketide Synthases; C041403:fusarin C; D010453:Peptide Synthases