Binuclear zinc transcription factors and the regulation of patulin biosynthesis in the filamentous Ascomycete Penicillium expansum

Sammanfattning: This thesis investigated the regulation of patulin production in Penicillium expansum in relation to fungal global regulators as well as the cluster-specific binuclear zinc transcription factor (BZTF) patL in silico. It also explored the state of BZTF research in filamentous ascomycetes fungi, and questioned if results in Saccharomyces cerevisiae can be freely translated to other taxonomic groups. Results indicate that a similar percentage of BZTFs bind as homodimers in filamentous ascomycetes as in S. cerevisiae, however, they also suggest that BZTFs are more prone to bind as monomers than previously thought, which could be beneficial in binding site prediction. However, the results are inconclusive if the presence of a coiled-coil domain can be used to predict the type of binding site. Global regulators are involved in a complex regulation system of patulin and 5'- CCBRAAGGAG -3' is identified as a putative binding motif for patL. A new generation of meta binding site prediction tools is proposed.